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ZFS(8)                  FreeBSD System Manager's Manual                 ZFS(8)

NAME
     zfs - configures ZFS file systems

SYNOPSIS
     zfs [-?]
     zfs create [-p] [-o property=value]... filesystem
     zfs create [-ps] [-b blocksize] [-o property=value]... -V size volume
     zfs destroy [-fnpRrv] filesystem|volume
     zfs destroy [-dnpRrv] filesystem|volume@snap[%snap][,snap[%snap]][,...]
     zfs destroy filesystem|volume#bookmark
     zfs snapshot|snap [-r] [-o property=value]...
         filesystem@snapname|volume@snapname
         filesystem@snapname|volume@snapname...
     zfs rollback [-rRf] snapshot
     zfs clone [-p] [-o property=value]... snapshot filesystem|volume
     zfs promote clone-filesystem
     zfs rename [-f] filesystem|volume|snapshot filesystem|volume|snapshot
     zfs rename [-f] -p filesystem|volume filesystem|volume
     zfs rename -r snapshot snapshot
     zfs rename -u [-p] filesystem filesystem
     zfs list [-r|-d depth] [-Hp] [-o property[,property]...]
         [-t type[,type]...] [-s property]... [-S property]...
         filesystem|volume|snapshot
     zfs set property=value filesystem|volume|snapshot...
     zfs get [-r|-d depth] [-Hp] [-o all | field[,field]...]
         [-t type[, type]...] [-s source[,source]...]
         all | property[,property]... filesystem|volume|snapshot...
     zfs inherit [-rS] property filesystem|volume|snapshot...
     zfs upgrade [-v]
     zfs upgrade [-r] [-V version] -a | filesystem
     zfs userspace [-Hinp] [-o field[,field]...] [-s field]... [-S field]...
         [-t type[,type]...] filesystem|snapshot
     zfs groupspace [-Hinp] [-o field[,field]...] [-s field]... [-S field]...
         [-t type[,type]...] filesystem|snapshot
     zfs mount
     zfs mount [-vO] [-o property[,property]...] -a | filesystem
     zfs unmount|umount [-f] -a | filesystem|mountpoint
     zfs share -a | filesystem
     zfs unshare -a | filesystem|mountpoint
     zfs bookmark snapshot bookmark
     zfs send [-DnPpRv] [-i snapshot | -I snapshot] snapshot
     zfs send [-i snapshot|bookmark] filesystem|volume|snapshot
     zfs receive|recv [-vnFu] filesystem|volume|snapshot
     zfs receive|recv [-vnFu] [-d | -e] filesystem
     zfs allow filesystem|volume
     zfs allow [-ldug] user|group[,user|group]...
         perm|@setname[,perm|@setname]... filesystem|volume
     zfs allow [-ld] -e|everyone perm|@setname[,perm|@setname]...
         filesystem|volume
     zfs allow -c perm|@setname[,perm|@setname]... filesystem|volume
     zfs allow -s @setname perm|@setname[,perm|@setname]... filesystem|volume
     zfs unallow [-rldug] user|group[,user|group]...
         [perm|@setname[,perm|@setname]...] filesystem|volume
     zfs unallow [-rld] -e|everyone [perm|@setname[,perm|@setname]...]
         filesystem|volume
     zfs unallow [-r] -c [perm|@setname[,perm|@setname]...] filesystem|volume
     zfs unallow [-r] -s @setname [perm|@setname[,perm|@setname]...]
         filesystem|volume
     zfs hold [-r] tag snapshot...
     zfs holds [-r] snapshot...
     zfs release [-r] tag snapshot...
     zfs diff [-FHt] snapshot [snapshot|filesystem]
     zfs jail jailid|jailname filesystem
     zfs unjail jailid|jailname filesystem

DESCRIPTION
     The zfs command configures ZFS datasets within a ZFS storage pool, as
     described in zpool(8).  A dataset is identified by a unique path within
     the ZFS namespace. For example:

         pool/{filesystem,volume,snapshot}

     where the maximum length of a dataset name is MAXNAMELEN (256 bytes).

     A dataset can be one of the following:

     file system   A ZFS dataset of type filesystem can be mounted within the
                   standard system namespace and behaves like other file
                   systems. While ZFS file systems are designed to be POSIX
                   compliant, known issues exist that prevent compliance in
                   some cases.  Applications that depend on standards
                   conformance might fail due to nonstandard behavior when
                   checking file system free space.

     volume        A logical volume exported as a raw or block device. This
                   type of dataset should only be used under special
                   circumstances. File systems are typically used in most
                   environments.

     snapshot      A read-only version of a file system or volume at a given
                   point in time. It is specified as filesystem@name or
                   volume@name.

   ZFS File System Hierarchy
     A ZFS storage pool is a logical collection of devices that provide space
     for datasets. A storage pool is also the root of the ZFS file system
     hierarchy.

     The root of the pool can be accessed as a file system, such as mounting
     and unmounting, taking snapshots, and setting properties. The physical
     storage characteristics, however, are managed by the zpool(8) command.

     See zpool(8) for more information on creating and administering pools.

   Snapshots
     A snapshot is a read-only copy of a file system or volume. Snapshots can
     be created extremely quickly, and initially consume no additional space
     within the pool. As data within the active dataset changes, the snapshot
     consumes more data than would otherwise be shared with the active
     dataset.

     Snapshots can have arbitrary names. Snapshots of volumes can be cloned or
     rolled back, but cannot be accessed independently.

     File system snapshots can be accessed under the .zfs/snapshot directory
     in the root of the file system. Snapshots are automatically mounted on
     demand and may be unmounted at regular intervals. The visibility of the
     .zfs directory can be controlled by the snapdir property.

   Clones
     A clone is a writable volume or file system whose initial contents are
     the same as another dataset. As with snapshots, creating a clone is
     nearly instantaneous, and initially consumes no additional space.

     Clones can only be created from a snapshot. When a snapshot is cloned, it
     creates an implicit dependency between the parent and child. Even though
     the clone is created somewhere else in the dataset hierarchy, the
     original snapshot cannot be destroyed as long as a clone exists. The
     origin property exposes this dependency, and the destroy command lists
     any such dependencies, if they exist.

     The clone parent-child dependency relationship can be reversed by using
     the promote subcommand. This causes the "origin" file system to become a
     clone of the specified file system, which makes it possible to destroy
     the file system that the clone was created from.

   Mount Points
     Creating a ZFS file system is a simple operation, so the number of file
     systems per system is likely to be numerous. To cope with this, ZFS
     automatically manages mounting and unmounting file systems without the
     need to edit the /etc/fstab file. All automatically managed file systems
     are mounted by ZFS at boot time.

     By default, file systems are mounted under /path, where path is the name
     of the file system in the ZFS namespace. Directories are created and
     destroyed as needed.

     A file system can also have a mount point set in the mountpoint property.
     This directory is created as needed, and ZFS automatically mounts the
     file system when the "zfs mount -a" command is invoked (without editing
     /etc/fstab).  The mountpoint property can be inherited, so if pool/home
     has a mount point of /home, then pool/home/user automatically inherits a
     mount point of /home/user.

     A file system mountpoint property of none prevents the file system from
     being mounted.

     If needed, ZFS file systems can also be managed with traditional tools
     (mount(8), umount(8), fstab(5)).  If a file system's mount point is set
     to legacy, ZFS makes no attempt to manage the file system, and the
     administrator is responsible for mounting and unmounting the file system.

   Jails
     A ZFS dataset can be attached to a jail by using the "zfs jail"
     subcommand. You cannot attach a dataset to one jail and the children of
     the same dataset to another jails. To allow management of the dataset
     from within a jail, the jailed property has to be set. The quota property
     cannot be changed from within a jail.

     A ZFS dataset can be detached from a jail using the "zfs unjail"
     subcommand.

     After a dataset is attached to a jail and the jailed property is set, a
     jailed file system cannot be mounted outside the jail, since the jail
     administrator might have set the mount point to an unacceptable value.

   Deduplication
     Deduplication is the process for removing redundant data at the block-
     level, reducing the total amount of data stored. If a file system has the
     dedup property enabled, duplicate data blocks are removed synchronously.
     The result is that only unique data is stored and common components are
     shared among files.

   Native Properties
     Properties are divided into two types, native properties and user-defined
     (or "user") properties. Native properties either export internal
     statistics or control ZFS behavior. In addition, native properties are
     either editable or read-only. User properties have no effect on ZFS
     behavior, but you can use them to annotate datasets in a way that is
     meaningful in your environment. For more information about user
     properties, see the "User Properties" section, below.

     Every dataset has a set of properties that export statistics about the
     dataset as well as control various behaviors. Properties are inherited
     from the parent unless overridden by the child. Some properties apply
     only to certain types of datasets (file systems, volumes, or snapshots).

     The values of numeric properties can be specified using human-readable
     suffixes (for example, k, KB, M, Gb, and so forth, up to Z for
     zettabyte). The following are all valid (and equal) specifications:

         1536M, 1.5g, 1.50GB

     The values of non-numeric properties are case sensitive and must be
     lowercase, except for mountpoint, sharenfs, and sharesmb.

     The following native properties consist of read-only statistics about the
     dataset. These properties can be neither set, nor inherited. Native
     properties apply to all dataset types unless otherwise noted.

     available
         The amount of space available to the dataset and all its children,
         assuming that there is no other activity in the pool. Because space
         is shared within a pool, availability can be limited by any number of
         factors, including physical pool size, quotas, reservations, or other
         datasets within the pool.

         This property can also be referred to by its shortened column name,
         avail.

     compressratio
         For non-snapshots, the compression ratio achieved for the used space
         of this dataset, expressed as a multiplier.  The used property
         includes descendant datasets, and, for clones, does not include the
         space shared with the origin snapshot.  For snapshots, the
         compressratio is the same as the refcompressratio property.
         Compression can be turned on by running: "zfs set compression=on
         dataset" The default value is off.

     creation
         The time this dataset was created.

     clones
         For snapshots, this property is a comma-separated list of filesystems
         or volumes which are clones of this snapshot.  The clones' origin
         property is this snapshot.  If the clones property is not empty, then
         this snapshot can not be destroyed (even with the -r or -f options).

     defer_destroy
         This property is on if the snapshot has been marked for deferred
         destroy by using the "zfs destroy -d" command. Otherwise, the
         property is off.

     filesystem_count
         The total number of filesystems and volumes that exist under this
         location in the dataset tree.  This value is only available when a
         filesystem_limit has been set somewhere in the tree under which the
         dataset resides.

     logicalreferenced
         The amount of space that is "logically" accessible by this dataset.
         See the referenced property.  The logical space ignores the effect of
         the compression and copies properties, giving a quantity closer to
         the amount of data that applications see.  However, it does include
         space consumed by metadata.

         This property can also be referred to by its shortened column name,
         lrefer.

     logicalused
         The amount of space that is "logically" consumed by this dataset and
         all its descendents.  See the used property.  The logical space
         ignores the effect of the compression and copies properties, giving a
         quantity closer to the amount of data that applications see.

         This property can also be referred to by its shortened column name,
         lused.

     mounted
         For file systems, indicates whether the file system is currently
         mounted. This property can be either yes or no.

     origin
         For cloned file systems or volumes, the snapshot from which the clone
         was created. See also the clones property.

     referenced
         The amount of data that is accessible by this dataset, which may or
         may not be shared with other datasets in the pool. When a snapshot or
         clone is created, it initially references the same amount of space as
         the file system or snapshot it was created from, since its contents
         are identical.

         This property can also be referred to by its shortened column name,
         refer.

     refcompressratio
         The compression ratio achieved for the referenced space of this
         dataset, expressed as a multiplier.  See also the compressratio
         property.

     snapshot_count
         The total number of snapshots that exist under this location in the
         dataset tree.  This value is only available when a snapshot_limit has
         been set somewhere in the tree under which the dataset resides.

     type
         The type of dataset: filesystem, volume, or snapshot.

     used
         The amount of space consumed by this dataset and all its descendents.
         This is the value that is checked against this dataset's quota and
         reservation. The space used does not include this dataset's
         reservation, but does take into account the reservations of any
         descendent datasets. The amount of space that a dataset consumes from
         its parent, as well as the amount of space that are freed if this
         dataset is recursively destroyed, is the greater of its space used
         and its reservation.

         When snapshots (see the "Snapshots" section) are created, their space
         is initially shared between the snapshot and the file system, and
         possibly with previous snapshots. As the file system changes, space
         that was previously shared becomes unique to the snapshot, and
         counted in the snapshot's space used. Additionally, deleting
         snapshots can increase the amount of space unique to (and used by)
         other snapshots.

         The amount of space used, available, or referenced does not take into
         account pending changes. Pending changes are generally accounted for
         within a few seconds. Committing a change to a disk using fsync(2) or
         O_SYNC does not necessarily guarantee that the space usage
         information is updated immediately.

     usedby*
         The usedby* properties decompose the used properties into the various
         reasons that space is used. Specifically, used = usedbysnapshots +
         usedbydataset + usedbychildren + usedbyrefreservation.  These
         properties are only available for datasets created with ZFS pool
         version 13 pools and higher.

     usedbysnapshots
         The amount of space consumed by snapshots of this dataset. In
         particular, it is the amount of space that would be freed if all of
         this dataset's snapshots were destroyed. Note that this is not simply
         the sum of the snapshots' used properties because space can be shared
         by multiple snapshots.

     usedbydataset
         The amount of space used by this dataset itself, which would be freed
         if the dataset were destroyed (after first removing any
         refreservation and destroying any necessary snapshots or
         descendents).

     usedbychildren
         The amount of space used by children of this dataset, which would be
         freed if all the dataset's children were destroyed.

     usedbyrefreservation
         The amount of space used by a refreservation set on this dataset,
         which would be freed if the refreservation was removed.

     userused@user
         The amount of space consumed by the specified user in this dataset.
         Space is charged to the owner of each file, as displayed by "ls -l".
         The amount of space charged is displayed by "du" and "ls -s".  See
         the "zfs userspace" subcommand for more information.

         Unprivileged users can access only their own space usage. The root
         user, or a user who has been granted the userused privilege with "zfs
         allow", can access everyone's usage.

         The userused@... properties are not displayed by "zfs get all".  The
         user's name must be appended after the @ symbol, using one of the
         following forms:

           +o   POSIX name (for example, joe)

           +o   POSIX numeric ID (for example, 1001)

     userrefs
         This property is set to the number of user holds on this snapshot.
         User holds are set by using the "zfs hold" command.

     groupused@group
         The amount of space consumed by the specified group in this dataset.
         Space is charged to the group of each file, as displayed by ls -l.
         See the userused@user property for more information.

         Unprivileged users can only access their own groups' space usage. The
         root user, or a user who has been granted the groupused privilege
         with "zfs allow", can access all groups' usage.

     volblocksize=blocksize
         For volumes, specifies the block size of the volume. The blocksize
         cannot be changed once the volume has been written, so it should be
         set at volume creation time. The default blocksize for volumes is 8
         Kbytes. Any power of 2 from 512 bytes to 128 Kbytes is valid.

         This property can also be referred to by its shortened column name,
         volblock.

     written
         The amount of referenced space written to this dataset since the
         previous snapshot.

     written@snapshot
         The amount of referenced space written to this dataset since the
         specified snapshot.  This is the space that is referenced by this
         dataset but was not referenced by the specified snapshot.

         The snapshot may be specified as a short snapshot name (just the part
         after the @), in which case it will be interpreted as a snapshot in
         the same filesystem as this dataset. The snapshot may be a full
         snapshot name (filesystem@snapshot), which for clones may be a
         snapshot in the origin's filesystem (or the origin of the origin's
         filesystem, etc).

     The following native properties can be used to change the behavior of a
     ZFS dataset.

     aclinherit=discard | noallow | restricted | passthrough | passthrough-x
         Controls how ACL entries are inherited when files and directories are
         created. A file system with an aclinherit property of discard does
         not inherit any ACL entries. A file system with an aclinherit
         property value of noallow only inherits inheritable ACL entries that
         specify "deny" permissions. The property value restricted (the
         default) removes the write_acl and write_owner permissions when the
         ACL entry is inherited. A file system with an aclinherit property
         value of passthrough inherits all inheritable ACL entries without any
         modifications made to the ACL entries when they are inherited. A file
         system with an aclinherit property value of passthrough-x has the
         same meaning as passthrough, except that the owner@, group@, and
         everyone@ ACEs inherit the execute permission only if the file
         creation mode also requests the execute bit.

         When the property value is set to passthrough, files are created with
         a mode determined by the inheritable ACEs. If no inheritable ACEs
         exist that affect the mode, then the mode is set in accordance to the
         requested mode from the application.

     aclmode=discard | groupmask | passthrough | restricted
         Controls how an ACL is modified during chmod(2).  A file system with
         an aclmode property of discard (the default) deletes all ACL entries
         that do not represent the mode of the file. An aclmode property of
         groupmask reduces permissions granted in all ALLOW entries found in
         the ACL such that they are no greater than the group permissions
         specified by chmod(2).  A file system with an aclmode property of
         passthrough indicates that no changes are made to the ACL other than
         creating or updating the necessary ACL entries to represent the new
         mode of the file or directory.  An aclmode property of restricted
         will cause the chmod(2) operation to return an error when used on any
         file or directory which has a non-trivial ACL whose entries can not
         be represented by a mode.  chmod(2) is required to change the set
         user ID, set group ID, or sticky bits on a file or directory, as they
         do not have equivalent ACL entries.  In order to use chmod(2) on a
         file or directory with a non-trivial ACL when aclmode is set to
         restricted, you must first remove all ACL entries which do not
         represent the current mode.

     atime=on | off
         Controls whether the access time for files is updated when they are
         read.  Turning this property off avoids producing write traffic when
         reading files and can result in significant performance gains, though
         it might confuse mailers and other similar utilities. The default
         value is on.

     canmount=on | off | noauto
         If this property is set to off, the file system cannot be mounted,
         and is ignored by "zfs mount -a".  Setting this property to off is
         similar to setting the mountpoint property to none, except that the
         dataset still has a normal mountpoint property, which can be
         inherited. Setting this property to off allows datasets to be used
         solely as a mechanism to inherit properties. One example of setting
         canmount=off is to have two datasets with the same mountpoint, so
         that the children of both datasets appear in the same directory, but
         might have different inherited characteristics.

         When the noauto value is set, a dataset can only be mounted and
         unmounted explicitly. The dataset is not mounted automatically when
         the dataset is created or imported, nor is it mounted by the "zfs
         mount -a" command or unmounted by the "zfs umount -a" command.

         This property is not inherited.

     checksum=on | off | fletcher2 | fletcher4 | sha256 | noparity
         Controls the checksum used to verify data integrity. The default
         value is on, which automatically selects an appropriate algorithm
         (currently, fletcher4, but this may change in future releases). The
         value off disables integrity checking on user data.  The value
         noparity not only disables integrity but also disables maintaining
         parity for user data.  This setting is used internally by a dump
         device residing on a RAID-Z pool and should not be used by any other
         dataset.  Disabling checksums is NOT a recommended practice.

     compression=on | off | lzjb | gzip | gzip-N | zle | lz4
         Controls the compression algorithm used for this dataset. The
         compression algorithm is optimized for performance while providing
         decent data compression. Setting compression to on uses the lzjb
         compression algorithm. The gzip compression algorithm uses the same
         compression as the gzip(1) command. You can specify the gzip level by
         using the value gzip-N where N is an integer from 1 (fastest) to 9
         (best compression ratio). Currently, gzip is equivalent to gzip-6
         (which is also the default for gzip(1)).  The zle compression
         algorithm compresses runs of zeros.

         The lz4 compression algorithm is a high-performance replacement for
         the lzjb algorithm. It features significantly faster compression and
         decompression, as well as a moderately higher compression ratio than
         lzjb, but can only be used on pools with the lz4_compress feature set
         to enabled.  See zpool-features(7) for details on ZFS feature flags
         and the lz4_compress feature.

         This property can also be referred to by its shortened column name
         compress.  Changing this property affects only newly-written data.

     copies=1 | 2 | 3
         Controls the number of copies of data stored for this dataset. These
         copies are in addition to any redundancy provided by the pool, for
         example, mirroring or RAID-Z. The copies are stored on different
         disks, if possible. The space used by multiple copies is charged to
         the associated file and dataset, changing the used property and
         counting against quotas and reservations.

         Changing this property only affects newly-written data. Therefore,
         set this property at file system creation time by using the -o
         copies=N option.

     dedup=on | off | verify | sha256[,verify]
         Configures deduplication for a dataset. The default value is off.
         The default deduplication checksum is sha256 (this may change in the
         future).  When dedup is enabled, the checksum defined here overrides
         the checksum property. Setting the value to verify has the same
         effect as the setting sha256,verify.

         If set to verify, ZFS will do a byte-to-byte comparsion in case of
         two blocks having the same signature to make sure the block contents
         are identical.

     devices=on | off
         The devices property is currently not supported on FreeBSD.

     exec=on | off
         Controls whether processes can be executed from within this file
         system. The default value is on.

     mlslabel=label | none
         The mlslabel property is currently not supported on FreeBSD.

     filesystem_limit=count | none
         Limits the number of filesystems and volumes that can exist under
         this point in the dataset tree.  The limit is not enforced if the
         user is allowed to change the limit.  Setting a filesystem_limit on a
         descendent of a filesystem that already has a filesystem_limit does
         not override the ancestor's filesystem_limit, but rather imposes an
         additional limit.  This feature must be enabled to be used (see
         zpool-features(7)).

     mountpoint=path | none | legacy
         Controls the mount point used for this file system. See the "Mount
         Points" section for more information on how this property is used.

         When the mountpoint property is changed for a file system, the file
         system and any children that inherit the mount point are unmounted.
         If the new value is legacy, then they remain unmounted. Otherwise,
         they are automatically remounted in the new location if the property
         was previously legacy or none, or if they were mounted before the
         property was changed. In addition, any shared file systems are
         unshared and shared in the new location.

     nbmand=on | off
         The nbmand property is currently not supported on FreeBSD.

     primarycache=all | none | metadata
         Controls what is cached in the primary cache (ARC). If this property
         is set to all, then both user data and metadata is cached. If this
         property is set to none, then neither user data nor metadata is
         cached. If this property is set to metadata, then only metadata is
         cached. The default value is all.

     quota=size | none
         Limits the amount of space a dataset and its descendents can consume.
         This property enforces a hard limit on the amount of space used. This
         includes all space consumed by descendents, including file systems
         and snapshots. Setting a quota on a descendent of a dataset that
         already has a quota does not override the ancestor's quota, but
         rather imposes an additional limit.

         Quotas cannot be set on volumes, as the volsize property acts as an
         implicit quota.

     snapshot_limit=count | none
         Limits the number of snapshots that can be created on a dataset and
         its descendents.  Setting a snapshot_limit on a descendent of a
         dataset that already has a snapshot_limit does not override the
         ancestor's snapshot_limit, but rather imposes an additional limit.
         The limit is not enforced if the user is allowed to change the limit.
         For example, this means that recursive snapshots taken from the
         global zone are counted against each delegated dataset within a jail.
         This feature must be enabled to be used (see zpool-features(7)).

     userquota@user=size | none
         Limits the amount of space consumed by the specified user.  Similar
         to the refquota property, the userquota space calculation does not
         include space that is used by descendent datasets, such as snapshots
         and clones. User space consumption is identified by the
         userspace@user property.

         Enforcement of user quotas may be delayed by several seconds. This
         delay means that a user might exceed their quota before the system
         notices that they are over quota and begins to refuse additional
         writes with the EDQUOT error message. See the userspace subcommand
         for more information.

         Unprivileged users can only access their own groups' space usage. The
         root user, or a user who has been granted the userquota privilege
         with "zfs allow", can get and set everyone's quota.

         This property is not available on volumes, on file systems before
         version 4, or on pools before version 15. The userquota@...
         properties are not displayed by "zfs get all".  The user's name must
         be appended after the @ symbol, using one of the following forms:

           +o   POSIX name (for example, joe)

           +o   POSIX numeric ID (for example, 1001)

     groupquota@group=size | none
         Limits the amount of space consumed by the specified group. Group
         space consumption is identified by the userquota@user property.

         Unprivileged users can access only their own groups' space usage. The
         root user, or a user who has been granted the groupquota privilege
         with "zfs allow", can get and set all groups' quotas.

     readonly=on | off
         Controls whether this dataset can be modified. The default value is
         off.

     recordsize=size
         Specifies a suggested block size for files in the file system. This
         property is designed solely for use with database workloads that
         access files in fixed-size records.  ZFS automatically tunes block
         sizes according to internal algorithms optimized for typical access
         patterns.

         For databases that create very large files but access them in small
         random chunks, these algorithms may be suboptimal. Specifying a
         recordsize greater than or equal to the record size of the database
         can result in significant performance gains. Use of this property for
         general purpose file systems is strongly discouraged, and may
         adversely affect performance.

         The size specified must be a power of two greater than or equal to
         512 and less than or equal to 128 Kbytes.

         Changing the file system's recordsize affects only files created
         afterward; existing files are unaffected.

         This property can also be referred to by its shortened column name,
         recsize.

     refquota=size | none
         Limits the amount of space a dataset can consume. This property
         enforces a hard limit on the amount of space used. This hard limit
         does not include space used by descendents, including file systems
         and snapshots.

     refreservation=size | none
         The minimum amount of space guaranteed to a dataset, not including
         its descendents. When the amount of space used is below this value,
         the dataset is treated as if it were taking up the amount of space
         specified by refreservation.  The refreservation reservation is
         accounted for in the parent datasets' space used, and counts against
         the parent datasets' quotas and reservations.

         If refreservation is set, a snapshot is only allowed if there is
         enough free pool space outside of this reservation to accommodate the
         current number of "referenced" bytes in the dataset.

         This property can also be referred to by its shortened column name,
         refreserv.

     reservation=size | none
         The minimum amount of space guaranteed to a dataset and its
         descendents. When the amount of space used is below this value, the
         dataset is treated as if it were taking up the amount of space
         specified by its reservation. Reservations are accounted for in the
         parent datasets' space used, and count against the parent datasets'
         quotas and reservations.

         This property can also be referred to by its shortened column name,
         reserv.

     secondarycache=all | none | metadata
         Controls what is cached in the secondary cache (L2ARC). If this
         property is set to all, then both user data and metadata is cached.
         If this property is set to none, then neither user data nor metadata
         is cached. If this property is set to metadata, then only metadata is
         cached. The default value is all.

     setuid=on | off
         Controls whether the set-UID bit is respected for the file system.
         The default value is on.

     sharesmb=on | off | opts
         The sharesmb property currently has no effect on FreeBSD.

     sharenfs=on | off | opts
         Controls whether the file system is shared via NFS, and what options
         are used. A file system with a sharenfs property of off is managed
         the traditional way via exports(5).  Otherwise, the file system is
         automatically shared and unshared with the "zfs share" and "zfs
         unshare" commands. If the property is set to on no NFS export options
         are used. Otherwise, NFS export options are equivalent to the
         contents of this property. The export options may be comma-separated.
         See exports(5) for a list of valid options.

         When the sharenfs property is changed for a dataset, the mountd(8)
         daemon is reloaded.

     logbias=latency | throughput
         Provide a hint to ZFS about handling of synchronous requests in this
         dataset.  If logbias is set to latency (the default), ZFS will use
         pool log devices (if configured) to handle the requests at low
         latency. If logbias is set to throughput, ZFS will not use configured
         pool log devices.  ZFS will instead optimize synchronous operations
         for global pool throughput and efficient use of resources.

     snapdir=hidden | visible
         Controls whether the .zfs directory is hidden or visible in the root
         of the file system as discussed in the "Snapshots" section. The
         default value is hidden.

     sync=standard | always | disabled
         Controls the behavior of synchronous requests (e.g.  fsync(2),
         O_DSYNC). This property accepts the following values:

             standard  This is the POSIX specified behavior of ensuring all
                       synchronous requests are written to stable storage and
                       all devices are flushed to ensure data is not cached by
                       device controllers (this is the default).

             always    All file system transactions are written and flushed
                       before their system calls return. This has a large
                       performance penalty.

             disabled  Disables synchronous requests. File system transactions
                       are only committed to stable storage periodically. This
                       option will give the highest performance.  However, it
                       is very dangerous as ZFS would be ignoring the
                       synchronous transaction demands of applications such as
                       databases or NFS.  Administrators should only use this
                       option when the risks are understood.

     volsize=size
         For volumes, specifies the logical size of the volume. By default,
         creating a volume establishes a reservation of equal size. For
         storage pools with a version number of 9 or higher, a refreservation
         is set instead. Any changes to volsize are reflected in an equivalent
         change to the reservation (or refreservation).  The volsize can only
         be set to a multiple of volblocksize, and cannot be zero.

         The reservation is kept equal to the volume's logical size to prevent
         unexpected behavior for consumers. Without the reservation, the
         volume could run out of space, resulting in undefined behavior or
         data corruption, depending on how the volume is used. These effects
         can also occur when the volume size is changed while it is in use
         (particularly when shrinking the size). Extreme care should be used
         when adjusting the volume size.

         Though not recommended, a "sparse volume" (also known as "thin
         provisioning") can be created by specifying the -s option to the "zfs
         create -V" command, or by changing the reservation after the volume
         has been created. A "sparse volume" is a volume where the reservation
         is less then the volume size.  Consequently, writes to a sparse
         volume can fail with ENOSPC when the pool is low on space. For a
         sparse volume, changes to volsize are not reflected in the
         reservation.

     vscan=off | on
         The vscan property is currently not supported on FreeBSD.

     xattr=off | on
         The xattr property is currently not supported on FreeBSD.

     jailed=off | on
         Controls whether the dataset is managed from a jail. See the "Jails"
         section for more information. The default value is off.

     The following three properties cannot be changed after the file system is
     created, and therefore, should be set when the file system is created. If
     the properties are not set with the "zfs create" or zpool create
     commands, these properties are inherited from the parent dataset. If the
     parent dataset lacks these properties due to having been created prior to
     these features being supported, the new file system will have the default
     values for these properties.

     casesensitivity=sensitive | insensitive | mixed
           Indicates whether the file name matching algorithm used by the file
           system should be case-sensitive, case-insensitive, or allow a
           combination of both styles of matching. The default value for the
           casesensitivity property is sensitive.  Traditionally, UNIX and
           POSIX file systems have case-sensitive file names.

           The mixed value for the casesensitivity property indicates that the
           file system can support requests for both case-sensitive and case-
           insensitive matching behavior.

     normalization=none | formC | formD | formKC | formKD
           Indicates whether the file system should perform a unicode
           normalization of file names whenever two file names are compared,
           and which normalization algorithm should be used. File names are
           always stored unmodified, names are normalized as part of any
           comparison process. If this property is set to a legal value other
           than none, and the utf8only property was left unspecified, the
           utf8only property is automatically set to on.  The default value of
           the normalization property is none.  This property cannot be
           changed after the file system is created.

     utf8only=on | off
           Indicates whether the file system should reject file names that
           include characters that are not present in the UTF-8 character code
           set. If this property is explicitly set to off, the normalization
           property must either not be explicitly set or be set to none.  The
           default value for the utf8only property is off.  This property
           cannot be changed after the file system is created.

     The casesensitivity, normalization, and utf8only properties are also new
     permissions that can be assigned to non-privileged users by using the ZFS
     delegated administration feature.

   Temporary Mount Point Properties
     When a file system is mounted, either through mount(8) for legacy mounts
     or the "zfs mount" command for normal file systems, its mount options are
     set according to its properties. The correlation between properties and
     mount options is as follows:

         PROPERTY    MOUNT OPTION
         atime       atime/noatime
         exec        exec/noexec
         readonly    ro/rw
         setuid      suid/nosuid

     In addition, these options can be set on a per-mount basis using the -o
     option, without affecting the property that is stored on disk. The values
     specified on the command line override the values stored in the dataset.
     These properties are reported as "temporary" by the "zfs get" command. If
     the properties are changed while the dataset is mounted, the new setting
     overrides any temporary settings.

   User Properties
     In addition to the standard native properties, ZFS supports arbitrary
     user properties. User properties have no effect on ZFS behavior, but
     applications or administrators can use them to annotate datasets (file
     systems, volumes, and snapshots).

     User property names must contain a colon (:) character to distinguish
     them from native properties. They may contain lowercase letters, numbers,
     and the following punctuation characters: colon (:), dash (-), period (.)
     and underscore (_).  The expected convention is that the property name is
     divided into two portions such as module:property, but this namespace is
     not enforced by ZFS.  User property names can be at most 256 characters,
     and cannot begin with a dash (-).

     When making programmatic use of user properties, it is strongly suggested
     to use a reversed DNS domain name for the module component of property
     names to reduce the chance that two independently-developed packages use
     the same property name for different purposes. Property names beginning
     with com.sun are reserved for use by Sun Microsystems.

     The values of user properties are arbitrary strings, are always
     inherited, and are never validated. All of the commands that operate on
     properties ("zfs list", "zfs get", "zfs set" and so forth) can be used to
     manipulate both native properties and user properties. Use the "zfs
     inherit" command to clear a user property. If the property is not defined
     in any parent dataset, it is removed entirely. Property values are
     limited to 1024 characters.

SUBCOMMANDS
     All subcommands that modify state are logged persistently to the pool in
     their original form.

     zfs [-?]

         Displays a help message.

     zfs create [-p] [-o property=value]... filesystem

         Creates a new ZFS file system. The file system is automatically
         mounted according to the mountpoint property inherited from the
         parent.

         -p      Creates all the non-existing parent datasets. Datasets
                 created in this manner are automatically mounted according to
                 the mountpoint property inherited from their parent. Any
                 property specified on the command line using the -o option is
                 ignored. If the target filesystem already exists, the
                 operation completes successfully.

         -o property=value
                 Sets the specified property as if the command "zfs set
                 property=value" was invoked at the same time the dataset was
                 created. Any editable ZFS property can also be set at
                 creation time. Multiple -o options can be specified. An error
                 results if the same property is specified in multiple -o
                 options.

     zfs create [-ps] [-b blocksize] [-o property=value]... -V size volume

         Creates a volume of the given size. The volume is exported as a block
         device in /dev/zvol/path, where path is the name of the volume in the
         ZFS namespace. The size represents the logical size as exported by
         the device. By default, a reservation of equal size is created.

         size is automatically rounded up to the nearest 128 Kbytes to ensure
         that the volume has an integral number of blocks regardless of
         blocksize.

         -p      Creates all the non-existing parent datasets. Datasets
                 created in this manner are automatically mounted according to
                 the mountpoint property inherited from their parent. Any
                 property specified on the command line using the -o option is
                 ignored. If the target filesystem already exists, the
                 operation completes successfully.

         -s      Creates a sparse volume with no reservation. See volsize in
                 the "Native Properties" section for more information about
                 sparse volumes.

         -b blocksize
                 Equivalent to -o volblocksize=blocksize.  If this option is
                 specified in conjunction with -o volblocksize, the resulting
                 behavior is undefined.

         -o property=value
                 Sets the specified property as if the "zfs set
                 property=value" command was invoked at the same time the
                 dataset was created. Any editable ZFS property can also be
                 set at creation time. Multiple -o options can be specified.
                 An error results if the same property is specified in
                 multiple -o options.

     zfs destroy [-fnpRrv] filesystem|volume

         Destroys the given dataset. By default, the command unshares any file
         systems that are currently shared, unmounts any file systems that are
         currently mounted, and refuses to destroy a dataset that has active
         dependents (children or clones).

         -r      Recursively destroy all children.

         -R      Recursively destroy all dependents, including cloned file
                 systems outside the target hierarchy.

         -f      Force an unmount of any file systems using the "zfs unmount
                 -f" command. This option has no effect on non-file systems or
                 unmounted file systems.

         -n      Do a dry-run ("No-op") deletion. No data will be deleted.
                 This is useful in conjunction with the -v or -p flags to
                 determine what data would be deleted.

         -p      Print machine-parsable verbose information about the deleted
                 data.

         -v      Print verbose information about the deleted data.

         Extreme care should be taken when applying either the -r or the -R
         options, as they can destroy large portions of a pool and cause
         unexpected behavior for mounted file systems in use.

     zfs destroy [-dnpRrv] snapshot[%snapname][,...]

         The given snapshots are destroyed immediately if and only if the "zfs
         destroy" command without the -d option would have destroyed it. Such
         immediate destruction would occur, for example, if the snapshot had
         no clones and the user-initiated reference count were zero.

         If a snapshot does not qualify for immediate destruction, it is
         marked for deferred deletion. In this state, it exists as a usable,
         visible snapshot until both of the preconditions listed above are
         met, at which point it is destroyed.

         An inclusive range of snapshots may be specified by separating the
         first and last snapshots with a percent sign (%).  The first and/or
         last snapshots may be left blank, in which case the filesystem's
         oldest or newest snapshot will be implied.

         Multiple snapshots (or ranges of snapshots) of the same filesystem or
         volume may be specified in a comma-separated list of snapshots.  Only
         the snapshot's short name (the part after the @) should be specified
         when using a range or comma-separated list to identify multiple
         snapshots.

         -r      Destroy (or mark for deferred deletion) all snapshots with
                 this name in descendent file systems.

         -R      Recursively destroy all clones of these snapshots, including
                 the clones, snapshots, and children.  If this flag is
                 specified, the [fl d] flag will have no effect.

         -n      Do a dry-run ("No-op") deletion. No data will be deleted.
                 This is useful in conjunction with the -v or -p flags to
                 determine what data would be deleted.

         -p      Print machine-parsable verbose information about the deleted
                 data.

         -v      Print verbose information about the deleted data.

         -d      Defer snapshot deletion.

         Extreme care should be taken when applying either the -r or the -R
         options, as they can destroy large portions of a pool and cause
         unexpected behavior for mounted file systems in use.

     zfs destroy filesystem|volume#bookmark

         The given bookmark is destroyed.

     zfs snapshot|snap [-r] [-o property=value]...
         filesystem@snapname|volume@snapname
         filesystem@snapname|volume@snapname...

         Creates snapshots with the given names. All previous modifications by
         successful system calls to the file system are part of the snapshots.
         Snapshots are taken atomically, so that all snapshots correspond to
         the same moment in time. See the "Snapshots" section for details.

         -r      Recursively create snapshots of all descendent datasets

         -o property=value
                 Sets the specified property; see "zfs create" for details.

     zfs rollback [-rRf] snapshot

         Roll back the given dataset to a previous snapshot. When a dataset is
         rolled back, all data that has changed since the snapshot is
         discarded, and the dataset reverts to the state at the time of the
         snapshot. By default, the command refuses to roll back to a snapshot
         other than the most recent one. In order to do so, all intermediate
         snapshots and bookmarks must be destroyed by specifying the -r
         option.

         The -rR options do not recursively destroy the child snapshots of a
         recursive snapshot.  Only direct snapshots of the specified
         filesystem are destroyed by either of these options.  To completely
         roll back a recursive snapshot, you must rollback the individual
         child snapshots.

         -r      Destroy any snapshots and bookmarks more recent than the one
                 specified.

         -R      Destroy any more recent snapshots and bookmarks, as well as
                 any clones of those snapshots.

         -f      Used with the -R option to force an unmount of any clone file
                 systems that are to be destroyed.

     zfs clone [-p] [-o property=value]... snapshot filesystem|volume

         Creates a clone of the given snapshot. See the "Clones" section for
         details. The target dataset can be located anywhere in the ZFS
         hierarchy, and is created as the same type as the original.

         -p      Creates all the non-existing parent datasets. Datasets
                 created in this manner are automatically mounted according to
                 the mountpoint property inherited from their parent. If the
                 target filesystem or volume already exists, the operation
                 completes successfully.

         -o property=value
                 Sets the specified property; see "zfs create" for details.

     zfs promote clone-filesystem

         Promotes a clone file system to no longer be dependent on its
         "origin" snapshot. This makes it possible to destroy the file system
         that the clone was created from. The clone parent-child dependency
         relationship is reversed, so that the origin file system becomes a
         clone of the specified file system.

         The snapshot that was cloned, and any snapshots previous to this
         snapshot, are now owned by the promoted clone. The space they use
         moves from the origin file system to the promoted clone, so enough
         space must be available to accommodate these snapshots. No new space
         is consumed by this operation, but the space accounting is adjusted.
         The promoted clone must not have any conflicting snapshot names of
         its own. The rename subcommand can be used to rename any conflicting
         snapshots.

     zfs rename [-f] filesystem|volume|snapshot filesystem|volume|snapshot

     zfs rename [-f] -p filesystem|volume filesystem|volume

     zfs rename -u [-p] filesystem filesystem

         Renames the given dataset. The new target can be located anywhere in
         the ZFS hierarchy, with the exception of snapshots. Snapshots can
         only be renamed within the parent file system or volume. When
         renaming a snapshot, the parent file system of the snapshot does not
         need to be specified as part of the second argument. Renamed file
         systems can inherit new mount points, in which case they are
         unmounted and remounted at the new mount point.

         -p      Creates all the nonexistent parent datasets. Datasets created
                 in this manner are automatically mounted according to the
                 mountpoint property inherited from their parent.

         -u      Do not remount file systems during rename. If a file system's
                 mountpoint property is set to legacy or none, file system is
                 not unmounted even if this option is not given.

         -f      Force unmount any filesystems that need to be unmounted in
                 the process.  This flag has no effect if used together with
                 the -u flag.

     zfs rename -r snapshot snapshot

         Recursively rename the snapshots of all descendent datasets.
         Snapshots are the only dataset that can be renamed recursively.

     zfs list [-r|-d depth] [-Hp] [-o property[,property]...] [-t
         type[,type]...] [-s property]... [-S property]...
         filesystem|volume|snapshot...

         Lists the property information for the given datasets in tabular
         form. If specified, you can list property information by the absolute
         pathname or the relative pathname. By default, all file systems and
         volumes are displayed.  Snapshots are displayed if the listsnaps
         property is on (the default is off).  The following fields are
         displayed, name, used, available, referenced, mountpoint.

         -r      Recursively display any children of the dataset on the
                 command line.

         -d depth
                 Recursively display any children of the dataset, limiting the
                 recursion to depth.  A depth of 1 will display only the
                 dataset and its direct children.

         -H      Used for scripting mode. Do not print headers and separate
                 fields by a single tab instead of arbitrary white space.

         -p      Display numbers in parsable (exact) values.

         -o property[,property]...
                 A comma-separated list of properties to display. The property
                 must be:

                   +o   One of the properties described in the "Native
                       Properties" section

                   +o   A user property

                   +o   The value name to display the dataset name

                   +o   The value space to display space usage properties on
                       file systems and volumes. This is a shortcut for
                       specifying -o
                       name,avail,used,usedsnap,usedds,usedrefreserv,usedchild
                       -t filesystem,volume syntax.

         -t type[,type]...
                 A comma-separated list of types to display, where type is one
                 of filesystem, snapshot, snap, volume, bookmark, or all.  For
                 example, specifying -t snapshot displays only snapshots.

         -s property
                 A property for sorting the output by column in ascending
                 order based on the value of the property. The property must
                 be one of the properties described in the "Properties"
                 section, or the special value name to sort by the dataset
                 name. Multiple properties can be specified at one time using
                 multiple -s property options. Multiple -s options are
                 evaluated from left to right in decreasing order of
                 importance.

                 The following is a list of sorting criteria:

                   +o   Numeric types sort in numeric order.

                   +o   String types sort in alphabetical order.

                   +o   Types inappropriate for a row sort that row to the
                       literal bottom, regardless of the specified ordering.

                   +o   If no sorting options are specified the existing
                       behavior of "zfs list" is preserved.

         -S property
                 Same as the -s option, but sorts by property in descending
                 order.

     zfs set property=value filesystem|volume|snapshot

         Sets the property to the given value for each dataset. Only some
         properties can be edited. See the "Properties" section for more
         information on what properties can be set and acceptable values.
         Numeric values can be specified as exact values, or in a human-
         readable form with a suffix of B, K, M, G, T, P, E, Z (for bytes,
         kilobytes, megabytes, gigabytes, terabytes, petabytes, exabytes, or
         zettabytes, respectively). User properties can be set on snapshots.
         For more information, see the "User Properties" section.

     zfs get [-r|-d depth] [-Hp] [-o all | field[,field]...] [-t
         type[,type]...] [-s source[,source]...] all | property[,property]...
         filesystem|volume|snapshot...

         Displays properties for the given datasets. If no datasets are
         specified, then the command displays properties for all datasets on
         the system. For each property, the following columns are displayed:

               name      Dataset name
               property  Property name
               value     Property value
               source    Property source. Can either be local, default,
                         temporary, inherited, or none (-).

         All columns except the RECEIVED column are displayed by default. The
         columns to display can be specified by using the -o option. This
         command takes a comma-separated list of properties as described in
         the "Native Properties" and "User Properties" sections.

         The special value all can be used to display all properties that
         apply to the given dataset's type (filesystem, volume, snapshot, or
         bookmark).

         -r      Recursively display properties for any children.

         -d depth
                 Recursively display any children of the dataset, limiting the
                 recursion to depth.  A depth of 1 will display only the
                 dataset and its direct children.

         -H      Display output in a form more easily parsed by scripts. Any
                 headers are omitted, and fields are explicitly separated by a
                 single tab instead of an arbitrary amount of space.

         -p      Display numbers in parsable (exact) values.

         -o all | field[,field]...
                 A comma-separated list of columns to display. Supported
                 values are name,property,value,received,source.  Default
                 values are name,property,value,source.  The keyword all
                 specifies all columns.

         -t type[,type]...
                 A comma-separated list of types to display, where type is one
                 of filesystem, snapshot, volume, or all.  For example,
                 specifying -t snapshot displays only snapshots.

         -s source[,source]...
                 A comma-separated list of sources to display. Those
                 properties coming from a source other than those in this list
                 are ignored. Each source must be one of the following:
                 local,default,inherited,temporary,received,none.  The default
                 value is all sources.

     zfs inherit [-rS] property filesystem|volume|snapshot...

         Clears the specified property, causing it to be inherited from an
         ancestor. If no ancestor has the property set, then the default value
         is used. See the "Properties" section for a listing of default
         values, and details on which properties can be inherited.

         -r      Recursively inherit the given property for all children.

         -S      For properties with a received value, revert to this value.
                 This flag has no effect on properties that do not have a
                 received value.

     zfs upgrade [-v]

         Displays a list of file systems that are not the most recent version.

         -v      Displays ZFS filesystem versions supported by the current
                 software. The current ZFS filesystem version and all previous
                 supported versions are displayed, along with an explanation
                 of the features provided with each version.

     zfs upgrade [-r] [-V version] -a | filesystem

         Upgrades file systems to a new on-disk version. Once this is done,
         the file systems will no longer be accessible on systems running
         older versions of the software.  "zfs send" streams generated from
         new snapshots of these file systems cannot be accessed on systems
         running older versions of the software.

         In general, the file system version is independent of the pool
         version. See zpool(8) for information on the zpool upgrade command.

         In some cases, the file system version and the pool version are
         interrelated and the pool version must be upgraded before the file
         system version can be upgraded.

         -r      Upgrade the specified file system and all descendent file
                 systems.

         -V version
                 Upgrade to the specified version.  If the -V flag is not
                 specified, this command upgrades to the most recent version.
                 This option can only be used to increase the version number,
                 and only up to the most recent version supported by this
                 software.

         -a      Upgrade all file systems on all imported pools.

         filesystem
                 Upgrade the specified file system.

     zfs userspace [-Hinp] [-o field[,field]...] [-s field]... [-S field]...
         [-t type[,type]...] filesystem|snapshot

         Displays space consumed by, and quotas on, each user in the specified
         filesystem or snapshot. This corresponds to the userused@user and
         userquota@user properties.

         -n      Print numeric ID instead of user/group name.

         -H      Do not print headers, use tab-delimited output.

         -p      Use exact (parsable) numeric output.

         -o field[,field]...
                 Display only the specified fields from the following set:
                 type,name,used,quota.  The default is to display all fields.

         -s field
                 Sort output by this field. The -s and -S flags may be
                 specified multiple times to sort first by one field, then by
                 another. The default is -s type -s name.

         -S field
                 Sort by this field in reverse order. See -s.

         -t type[,type]...
                 Print only the specified types from the following set:
                 all,posixuser,smbuser,posixgroup,smbgroup.

                 The default is -t posixuser,smbuser.

                 The default can be changed to include group types.

         -i      Translate SID to POSIX ID. This flag currently has no effect
                 on FreeBSD.

     zfs groupspace [-Hinp] [-o field[,field]...] [-s field]... [-S field]...
         [-t type[,type]...] filesystem|snapshot

         Displays space consumed by, and quotas on, each group in the
         specified filesystem or snapshot. This subcommand is identical to
         "zfs userspace", except that the default types to display are -t
         posixgroup,smbgroup.

     zfs mount

         Displays all ZFS file systems currently mounted.

         -f

     zfs mount [-vO] [-o property[,property]...] -a | filesystem

         Mounts ZFS file systems.

         -v      Report mount progress.

         -O      Perform an overlay mount. Overlay mounts are not supported on
                 FreeBSD.

         -o property[,property]...
                 An optional, comma-separated list of mount options to use
                 temporarily for the duration of the mount. See the "Temporary
                 Mount Point Properties" section for details.

         -a      Mount all available ZFS file systems.  This command may be
                 executed on FreeBSD system startup by /etc/rc.d/zfs.  For
                 more information, see variable zfs_enable in rc.conf(5).

         filesystem
                 Mount the specified filesystem.

     zfs unmount|umount [-f] -a | filesystem|mountpoint

         Unmounts currently mounted ZFS file systems.

         -f      Forcefully unmount the file system, even if it is currently
                 in use.

         -a      Unmount all available ZFS file systems.

         filesystem | mountpoint
                 Unmount the specified filesystem. The command can also be
                 given a path to a ZFS file system mount point on the system.

     zfs share -a | filesystem

         Shares ZFS file systems that have the sharenfs property set.

         -a      Share all ZFS file systems that have the sharenfs property
                 set.  This command may be executed on FreeBSD system startup
                 by /etc/rc.d/zfs.  For more information, see variable
                 zfs_enable in rc.conf(5).

         filesystem
                 Share the specified filesystem according to the sharenfs
                 property. File systems are shared when the sharenfs property
                 is set.

     zfs unshare -a | filesystem|mountpoint

         Unshares ZFS file systems that have the sharenfs property set.

         -a      Unshares ZFS file systems that have the sharenfs property
                 set.  This command may be executed on FreeBSD system shutdown
                 by /etc/rc.d/zfs.  For more information, see variable
                 zfs_enable in rc.conf(5).

         filesystem | mountpoint
                 Unshare the specified filesystem. The command can also be
                 given a path to a ZFS file system shared on the system.

     zfs bookmark snapshot bookmark

         Creates a bookmark of the given snapshot.  Bookmarks mark the point
         in time when the snapshot was created, and can be used as the
         incremental source for a "zfs send" command.

         This feature must be enabled to be used.  See zpool-features(7) for
         details on ZFS feature flags and the bookmark feature.

     zfs send [-DnPpRv] [-i snapshot | -I snapshot] snapshot

         Creates a stream representation of the last snapshot argument (not
         part of -i or -I) which is written to standard output. The output can
         be redirected to a file or to a different system (for example, using
         ssh(1)).  By default, a full stream is generated.

         -i snapshot
                 Generate an incremental stream from the first snapshot (the
                 incremental source) to the second snapshot (the incremental
                 target).  The incremental source can be specified as the last
                 component of the snapshot name (the @ character and
                 following) and it is assumed to be from the same file system
                 as the incremental target.

                 If the destination is a clone, the source may be the origin
                 snapshot, which must be fully specified (for example,
                 pool/fs@origin, not just @origin).

         -I snapshot
                 Generate a stream package that sends all intermediary
                 snapshots from the first snapshot to the second snapshot.
                 For example, -I @a fs@d is similar to -i @a fs@b; -i @b fs@c;
                 -i @c fs@d.  The incremental source may be specified as with
                 the -i option.

         -R      Generate a replication stream package, which will replicate
                 the specified filesystem, and all descendent file systems, up
                 to the named snapshot. When received, all properties,
                 snapshots, descendent file systems, and clones are preserved.

                 If the -i or -I flags are used in conjunction with the -R
                 flag, an incremental replication stream is generated. The
                 current values of properties, and current snapshot and file
                 system names are set when the stream is received. If the -F
                 flag is specified when this stream is received, snapshots and
                 file systems that do not exist on the sending side are
                 destroyed.

         -D      Generate a deduplicated stream. Blocks which would have been
                 sent multiple times in the send stream will only be sent
                 once.  The receiving system must also support this feature to
                 receive a deduplicated stream.  This flag can be used
                 regardless of the dataset's dedup property, but performance
                 will be much better if the filesystem uses a dedup-capable
                 checksum (eg.  sha256).

         -p      Include the dataset's properties in the stream. This flag is
                 implicit when -R is specified. The receiving system must also
                 support this feature.

         -n      Do a dry-run ("No-op") send.  Do not generate any actual send
                 data.  This is useful in conjunction with the -v or -P flags
                 to determine what data will be sent.

         -P      Print machine-parsable verbose information about the stream
                 package generated.

         -v      Print verbose information about the stream package generated.
                 This information includes a per-second report of how much
                 data has been sent.

         The format of the stream is committed. You will be able to receive
         your streams on future versions of ZFS.

     zfs send [-i snapshot|bookmark] filesystem|volume|snapshot

         Generate a send stream, which may be of a filesystem, and may be
         incremental from a bookmark.  If the destination is a filesystem or
         volume, the pool must be read-only, or the filesystem must not be
         mounted.  When the stream generated from a filesystem or volume is
         received, the default snapshot name will be (--head--).

         -i snapshot|bookmark
                 Generate an incremental send stream.  The incremental source
                 must be an earlier snapshot in the destination's history.  It
                 will commonly be an earlier snapshot in the destination's
                 filesystem, in which case it can be specified as the last
                 component of the name (the # or @ character and following).

                 If the incremental target is a clone, the incremental source
                 can be the origin snapshot, or an earlier snapshot in the
                 origin's filesystem, or the origin's origin, etc.

     zfs receive|recv [-vnFu] filesystem|volume|snapshot

     zfs receive|recv [-vnFu] [-d | -e] filesystem

         Creates a snapshot whose contents are as specified in the stream
         provided on standard input. If a full stream is received, then a new
         file system is created as well. Streams are created using the "zfs
         send" subcommand, which by default creates a full stream.  "zfs recv"
         can be used as an alias for "zfs receive".

         If an incremental stream is received, then the destination file
         system must already exist, and its most recent snapshot must match
         the incremental stream's source. For zvols, the destination device
         link is destroyed and recreated, which means the zvol cannot be
         accessed during the receive operation.

         When a snapshot replication package stream that is generated by using
         the "zfs send -R" command is received, any snapshots that do not
         exist on the sending location are destroyed by using the "zfs destroy
         -d" command.

         The name of the snapshot (and file system, if a full stream is
         received) that this subcommand creates depends on the argument type
         and the -d or -e option.

         If the argument is a snapshot name, the specified snapshot is
         created. If the argument is a file system or volume name, a snapshot
         with the same name as the sent snapshot is created within the
         specified filesystem or volume.  If the -d or -e option is specified,
         the snapshot name is determined by appending the sent snapshot's name
         to the specified filesystem.  If the -d option is specified, all but
         the pool name of the sent snapshot path is appended (for example,
         b/c@1 appended from sent snapshot a/b/c@1), and if the -e option is
         specified, only the tail of the sent snapshot path is appended (for
         example, c@1 appended from sent snapshot a/b/c@1).  In the case of
         -d, any file systems needed to replicate the path of the sent
         snapshot are created within the specified file system.

         -d      Use the full sent snapshot path without the first element
                 (without pool name) to determine the name of the new snapshot
                 as described in the paragraph above.

         -e      Use only the last element of the sent snapshot path to
                 determine the name of the new snapshot as described in the
                 paragraph above.

         -u      File system that is associated with the received stream is
                 not mounted.

         -v      Print verbose information about the stream and the time
                 required to perform the receive operation.

         -n      Do not actually receive the stream. This can be useful in
                 conjunction with the -v option to verify the name the receive
                 operation would use.

         -F      Force a rollback of the file system to the most recent
                 snapshot before performing the receive operation. If
                 receiving an incremental replication stream (for example, one
                 generated by "zfs send -R -Fi -iI"), destroy snapshots and
                 file systems that do not exist on the sending side.

     zfs allow filesystem|volume

         Displays permissions that have been delegated on the specified
         filesystem or volume. See the other forms of "zfs allow" for more
         information.

     zfs allow [-ldug] user|group[,user|group]...
         perm|@setname[,perm|@setname]... filesystem|volume

     zfs allow [-ld] -e|everyone perm|@setname[,perm|@setname]...
         filesystem|volume

         Delegates ZFS administration permission for the file systems to non-
         privileged users.

         [-ug] user|group[, user|group]...
                 Specifies to whom the permissions are delegated. Multiple
                 entities can be specified as a comma-separated list. If
                 neither of the -ug options are specified, then the argument
                 is interpreted preferentially as the keyword everyone, then
                 as a user name, and lastly as a group name. To specify a user
                 or group named "everyone", use the -u or -g options. To
                 specify a group with the same name as a user, use the -g
                 option.

         [-e|everyone]
                 Specifies that the permissions be delegated to "everyone".

         perm|@setname[,perm|@setname]...
                 The permissions to delegate. Multiple permissions may be
                 specified as a comma-separated list. Permission names are the
                 same as ZFS subcommand and property names. See the property
                 list below. Property set names, which begin with an at sign
                 (@), may be specified. See the -s form below for details.

         [-ld] filesystem|volume
                 Specifies where the permissions are delegated. If neither of
                 the -ld options are specified, or both are, then the
                 permissions are allowed for the file system or volume, and
                 all of its descendents. If only the -l option is used, then
                 is allowed "locally" only for the specified file system.  If
                 only the -d option is used, then is allowed only for the
                 descendent file systems.

         Permissions are generally the ability to use a ZFS subcommand or
         change a ZFS property. The following permissions are available:

             NAME              TYPE          NOTES
             allow             subcommand    Must also have the permission
                                             that is being allowed
             clone             subcommand    Must also have the 'create'
                                             ability and 'mount' ability in
                                             the origin file system
             create            subcommand    Must also have the 'mount'
                                             ability
             destroy           subcommand    Must also have the 'mount'
                                             ability
             diff              subcommand    Allows lookup of paths within a
                                             dataset given an object number,
                                             and the ability to create
                                             snapshots necessary to 'zfs diff'
             hold              subcommand    Allows adding a user hold to a
                                             snapshot
             mount             subcommand    Allows mount/umount of ZFS
                                             datasets
             promote           subcommand    Must also have the 'mount' and
                                             'promote' ability in the origin
                                             file system
             receive           subcommand    Must also have the 'mount' and
                                             'create' ability
             release           subcommand    Allows releasing a user hold
                                             which might destroy the snapshot
             rename            subcommand    Must also have the 'mount' and
                                             'create' ability in the new
                                             parent
             rollback          subcommand    Must also have the 'mount'
                                             ability
             send              subcommand
             share             subcommand    Allows sharing file systems over
                                             the NFS protocol
             snapshot          subcommand    Must also have the 'mount'
                                             ability
             groupquota        other         Allows accessing any
                                             groupquota@... property
             groupused         other         Allows reading any groupused@...
                                             property
             userprop          other         Allows changing any user property
             userquota         other         Allows accessing any
                                             userquota@... property
             userused          other         Allows reading any userused@...
                                             property
             aclinherit        property
             aclmode           property
             atime             property
             canmount          property
             casesensitivity   property
             checksum          property
             compression       property
             copies            property
             dedup             property
             devices           property
             exec              property
             filesystem_limit  property
             logbias           property
             jailed            property
             mlslabel          property
             mountpoint        property
             nbmand            property
             normalization     property
             primarycache      property
             quota             property
             readonly          property
             recordsize        property
             refquota          property
             refreservation    property
             reservation       property
             secondarycache    property
             setuid            property
             sharenfs          property
             sharesmb          property
             snapdir           property
             snapshot_limit    property
             sync              property
             utf8only          property
             version           property
             volblocksize      property
             volsize           property
             vscan             property
             xattr             property

     zfs allow -c perm|@setname[,perm|@setname]... filesystem|volume

         Sets "create time" permissions. These permissions are granted
         (locally) to the creator of any newly-created descendent file system.

     zfs allow -s @setname perm|@setname[,perm|@setname]... filesystem|volume

         Defines or adds permissions to a permission set. The set can be used
         by other "zfs allow" commands for the specified file system and its
         descendents. Sets are evaluated dynamically, so changes to a set are
         immediately reflected. Permission sets follow the same naming
         restrictions as ZFS file systems, but the name must begin with an "at
         sign" (@), and can be no more than 64 characters long.

     zfs unallow [-rldug] user|group[,user|group]...
         [perm|@setname[,perm|@setname]...] filesystem|volume

     zfs unallow [-rld] -e|everyone [perm|@setname[,perm|@setname]...]
         filesystem|volume

     zfs unallow [-r] -c [perm|@setname[,perm|@setname]...] filesystem|volume

         Removes permissions that were granted with the "zfs allow" command.
         No permissions are explicitly denied, so other permissions granted
         are still in effect. For example, if the permission is granted by an
         ancestor. If no permissions are specified, then all permissions for
         the specified user, group, or everyone are removed. Specifying
         everyone (or using the -e option) only removes the permissions that
         were granted to everyone, not all permissions for every user and
         group. See the "zfs allow" command for a description of the -ldugec
         options.

         -r      Recursively remove the permissions from this file system and
                 all descendents.

     zfs unallow [-r] -s @setname [perm|@setname[,perm|@setname]...]
         filesystem|volume

         Removes permissions from a permission set. If no permissions are
         specified, then all permissions are removed, thus removing the set
         entirely.

     zfs hold [-r] tag snapshot...

         Adds a single reference, named with the tag argument, to the
         specified snapshot or snapshots. Each snapshot has its own tag
         namespace, and tags must be unique within that space.

         If a hold exists on a snapshot, attempts to destroy that snapshot by
         using the "zfs destroy" command returns EBUSY.

         -r      Specifies that a hold with the given tag is applied
                 recursively to the snapshots of all descendent file systems.

     zfs holds [-r] snapshot...

         Lists all existing user references for the given snapshot or
         snapshots.

         -r      Lists the holds that are set on the named descendent
                 snapshots, in addition to listing the holds on the named
                 snapshot.

     zfs release [-r] tag snapshot...

         Removes a single reference, named with the tag argument, from the
         specified snapshot or snapshots. The tag must already exist for each
         snapshot.

         -r      Recursively releases a hold with the given tag on the
                 snapshots of all descendent file systems.

     zfs diff [-FHt] snapshot [snapshot|filesystem]

         Display the difference between a snapshot of a given filesystem and
         another snapshot of that filesystem from a later time or the current
         contents of the filesystem.  The first column is a character
         indicating the type of change, the other columns indicate pathname,
         new pathname (in case of rename), change in link count, and
         optionally file type and/or change time.

         The types of change are:

           -         path was removed
           +         path was added
           M         path was modified
           R         path was renamed

         -F      Display an indication of the type of file, in a manner
                 similar to the -F option of ls(1).

                   B         block device
                   C         character device
                   F         regular file
                   /         directory
                   @         symbolic link
                   =         socket
                   >         door (not supported on FreeBSD)
                   |         named pipe (not supported on FreeBSD)
                   P         event port (not supported on FreeBSD)

         -H      Give more parsable tab-separated output, without header lines
                 and without arrows.

         -t      Display the path's inode change time as the first column of
                 output.

     zfs jail jailid filesystem

         Attaches the specified filesystem to the jail identified by JID
         jailid.  From now on this file system tree can be managed from within
         a jail if the jailed property has been set. To use this
         functionality, the jail needs the enforce_statfs parameter set to 0
         and the allow.mount parameter set to 1.

         See jail(8) for more information on managing jails and configuring
         the parameters above.

     zfs unjail jailid filesystem

         Detaches the specified filesystem from the jail identified by JID
         jailid.

EXIT STATUS
     The following exit values are returned:

       0   Successful completion.

       1   An error occurred.

       2   Invalid command line options were specified.

EXAMPLES
     Example 1 Creating a ZFS File System Hierarchy

       The following commands create a file system named pool/home and a file
       system named pool/home/bob.  The mount point /home is set for the
       parent file system, and is automatically inherited by the child file
       system.

         # zfs create pool/home
         # zfs set mountpoint=/home pool/home
         # zfs create pool/home/bob

     Example 2 Creating a ZFS Snapshot

       The following command creates a snapshot named yesterday.  This
       snapshot is mounted on demand in the .zfs/snapshot directory at the
       root of the pool/home/bob file system.

         # zfs snapshot pool/home/bob@yesterday

     Example 3 Creating and Destroying Multiple Snapshots

       The following command creates snapshots named yesterday of pool/home
       and all of its descendent file systems. Each snapshot is mounted on
       demand in the .zfs/snapshot directory at the root of its file system.
       The second command destroys the newly created snapshots.

         # zfs snapshot -r pool/home@yesterday
         # zfs destroy -r pool/home@yesterday

     Example 4 Disabling and Enabling File System Compression

       The following command disables the compression property for all file
       systems under pool/home.  The next command explicitly enables
       compression for pool/home/anne.

         # zfs set compression=off pool/home
         # zfs set compression=on pool/home/anne

     Example 5 Listing ZFS Datasets

       The following command lists all active file systems and volumes in the
       system.  Snapshots are displayed if the listsnaps property is on.  The
       default is off.  See zpool(8) for more information on pool properties.

         # zfs list
            NAME                      USED  AVAIL  REFER  MOUNTPOINT
            pool                      450K   457G    18K  /pool
            pool/home                 315K   457G    21K  /home
            pool/home/anne             18K   457G    18K  /home/anne
            pool/home/bob             276K   457G   276K  /home/bob

     Example 6 Setting a Quota on a ZFS File System

       The following command sets a quota of 50 Gbytes for pool/home/bob.

         # zfs set quota=50G pool/home/bob

     Example 7 Listing ZFS Properties

       The following command lists all properties for pool/home/bob.

         # zfs get all pool/home/bob
         NAME           PROPERTY              VALUE                  SOURCE
         pool/home/bob  type                  filesystem             -
         pool/home/bob  creation              Tue Jul 21 15:53 2009  -
         pool/home/bob  used                  21K                    -
         pool/home/bob  available             20.0G                  -
         pool/home/bob  referenced            21K                    -
         pool/home/bob  compressratio         1.00x                  -
         pool/home/bob  mounted               yes                    -
         pool/home/bob  quota                 20G                    local
         pool/home/bob  reservation           none                   default
         pool/home/bob  recordsize            128K                   default
         pool/home/bob  mountpoint            /home/bob              default
         pool/home/bob  sharenfs              off                    default
         pool/home/bob  checksum              on                     default
         pool/home/bob  compression           on                     local
         pool/home/bob  atime                 on                     default
         pool/home/bob  devices               on                     default
         pool/home/bob  exec                  on                     default
         pool/home/bob  filesystem_limit      none                   default
         pool/home/bob  setuid                on                     default
         pool/home/bob  readonly              off                    default
         pool/home/bob  jailed                off                    default
         pool/home/bob  snapdir               hidden                 default
         pool/home/bob  snapshot_limit        none                   default
         pool/home/bob  aclmode               discard                default
         pool/home/bob  aclinherit            restricted             default
         pool/home/bob  canmount              on                     default
         pool/home/bob  xattr                 on                     default
         pool/home/bob  copies                1                      default
         pool/home/bob  version               5                      -
         pool/home/bob  utf8only              off                    -
         pool/home/bob  normalization         none                   -
         pool/home/bob  casesensitivity       sensitive              -
         pool/home/bob  vscan                 off                    default
         pool/home/bob  nbmand                off                    default
         pool/home/bob  sharesmb              off                    default
         pool/home/bob  refquota              none                   default
         pool/home/bob  refreservation        none                   default
         pool/home/bob  primarycache          all                    default
         pool/home/bob  secondarycache        all                    default
         pool/home/bob  usedbysnapshots       0                      -
         pool/home/bob  usedbydataset         21K                    -
         pool/home/bob  usedbychildren        0                      -
         pool/home/bob  usedbyrefreservation  0                      -
         pool/home/bob  logbias               latency                default
         pool/home/bob  dedup                 off                    default
         pool/home/bob  mlslabel                                     -
         pool/home/bob  sync                  standard               default
         pool/home/bob  refcompressratio      1.00x                  -

       The following command gets a single property value.

         # zfs get -H -o value compression pool/home/bob
         on

       The following command lists all properties with local settings for
       pool/home/bob.

         # zfs get -s local -o name,property,value all pool/home/bob
         NAME           PROPERTY              VALUE
         pool/home/bob  quota                 20G
         pool/home/bob  compression           on

     Example 8 Rolling Back a ZFS File System

       The following command reverts the contents of pool/home/anne to the
       snapshot named yesterday, deleting all intermediate snapshots.

         # zfs rollback -r pool/home/anne@yesterday

     Example 9 Creating a ZFS Clone

       The following command creates a writable file system whose initial
       contents are the same as pool/home/bob@yesterday.

         # zfs clone pool/home/bob@yesterday pool/clone

     Example 10 Promoting a ZFS Clone

       The following commands illustrate how to test out changes to a file
       system, and then replace the original file system with the changed one,
       using clones, clone promotion, and renaming:

         # zfs create pool/project/production

       Populate /pool/project/production with data and continue with the
       following commands:

         # zfs snapshot pool/project/production@today
         # zfs clone pool/project/production@today pool/project/beta

       Now make changes to /pool/project/beta and continue with the following
       commands:

         # zfs promote pool/project/beta
         # zfs rename pool/project/production pool/project/legacy
         # zfs rename pool/project/beta pool/project/production

       Once the legacy version is no longer needed, it can be destroyed.

         # zfs destroy pool/project/legacy

     Example 11 Inheriting ZFS Properties

       The following command causes pool/home/bob and pool/home/anne to
       inherit the checksum property from their parent.

         # zfs inherit checksum pool/home/bob pool/home/anne

     Example 12 Remotely Replicating ZFS Data

       The following commands send a full stream and then an incremental
       stream to a remote machine, restoring them into poolB/received/fs@a and
       poolB/received/fs@b, respectively.  poolB must contain the file system
       poolB/received, and must not initially contain poolB/received/fs.

         # zfs send pool/fs@a | ssh host zfs receive poolB/received/fs@a
         # zfs send -i a pool/fs@b | ssh host zfs receive poolB/received/fs

     Example 13 Using the "zfs receive -d" Option

       The following command sends a full stream of poolA/fsA/fsB@snap to a
       remote machine, receiving it into poolB/received/fsA/fsB@snap.  The
       fsA/fsB@snap portion of the received snapshot's name is determined from
       the name of the sent snapshot.  poolB must contain the file system
       poolB/received.  If poolB/received/fsA does not exist, it is created as
       an empty file system.

         # zfs send poolA/fsA/fsB@snap | ssh host zfs receive -d poolB/received

     Example 14 Setting User Properties

       The following example sets the user-defined com.example:department
       property for a dataset.

         # zfs set com.example:department=12345 tank/accounting

     Example 15 Performing a Rolling Snapshot

       The following example shows how to maintain a history of snapshots with
       a consistent naming scheme. To keep a week's worth of snapshots, the
       user destroys the oldest snapshot, renames the remaining snapshots, and
       then creates a new snapshot, as follows:

         # zfs destroy -r pool/users@7daysago
         # zfs rename -r pool/users@6daysago @7daysago
         # zfs rename -r pool/users@5daysago @6daysago
         # zfs rename -r pool/users@4daysago @5daysago
         # zfs rename -r pool/users@3daysago @4daysago
         # zfs rename -r pool/users@2daysago @3daysago
         # zfs rename -r pool/users@yesterday @2daysago
         # zfs rename -r pool/users@today @yesterday
         # zfs snapshot -r pool/users@today

     Example 16 Setting "sharenfs" Property Options on a ZFS File System

       The following command shows how to set sharenfs property options to
       enable root access for a specific network on the tank/home file system.
       The contents of the sharenfs property are valid exports(5) options.

         # zfs set sharenfs="maproot=root,network 192.168.0.0/24" tank/home

       Another way to write this command with the same result is:

         # set zfs sharenfs="-maproot=root -network 192.168.0.0/24" tank/home

     Example 17 Delegating ZFS Administration Permissions on a ZFS Dataset

       The following example shows how to set permissions so that user cindys
       can create, destroy, mount, and take snapshots on tank/cindys.  The
       permissions on tank/cindys are also displayed.

         # zfs allow cindys create,destroy,mount,snapshot tank/cindys
         # zfs allow tank/cindys
         -------------------------------------------------------------
         Local+Descendent permissions on (tank/cindys)
                   user cindys create,destroy,mount,snapshot
         -------------------------------------------------------------

     Example 18 Delegating Create Time Permissions on a ZFS Dataset

       The following example shows how to grant anyone in the group staff to
       create file systems in tank/users.  This syntax also allows staff
       members to destroy their own file systems, but not destroy anyone
       else's file system. The permissions on tank/users are also displayed.

         # zfs allow staff create,mount tank/users
         # zfs allow -c destroy tank/users
         # zfs allow tank/users
         -------------------------------------------------------------
         Create time permissions on (tank/users)
                   create,destroy
         Local+Descendent permissions on (tank/users)
                   group staff create,mount
         -------------------------------------------------------------

     Example 19 Defining and Granting a Permission Set on a ZFS Dataset

       The following example shows how to define and grant a permission set on
       the tank/users file system. The permissions on tank/users are also
       displayed.

         # zfs allow -s @pset create,destroy,snapshot,mount tank/users
         # zfs allow staff @pset tank/users
         # zfs allow tank/users
         -------------------------------------------------------------
         Permission sets on (tank/users)
                 @pset create,destroy,mount,snapshot
         Create time permissions on (tank/users)
                 create,destroy
         Local+Descendent permissions on (tank/users)
                 group staff @pset,create,mount
         -------------------------------------------------------------

     Example 20 Delegating Property Permissions on a ZFS Dataset

       The following example shows to grant the ability to set quotas and
       reservations on the users/home file system. The permissions on
       users/home are also displayed.

         # zfs allow cindys quota,reservation users/home
         # zfs allow cindys
         -------------------------------------------------------------
         Local+Descendent permissions on (users/home)
                 user cindys quota,reservation
         -------------------------------------------------------------
         # su - cindys
         cindys% zfs set quota=10G users/home/marks
         cindys% zfs get quota users/home/marks
         NAME              PROPERTY  VALUE             SOURCE
         users/home/marks  quota     10G               local

     Example 21 Removing ZFS Delegated Permissions on a ZFS Dataset

       The following example shows how to remove the snapshot permission from
       the staff group on the tank/users file system. The permissions on
       tank/users are also displayed.

         # zfs unallow staff snapshot tank/users
         # zfs allow tank/users
         -------------------------------------------------------------
         Permission sets on (tank/users)
                 @pset create,destroy,mount,snapshot
         Create time permissions on (tank/users)
                 create,destroy
         Local+Descendent permissions on (tank/users)
                 group staff @pset,create,mount
         -------------------------------------------------------------

     Example 22 Showing the differences between a snapshot and a ZFS Dataset

       The following example shows how to see what has changed between a prior
       snapshot of a ZFS Dataset and its current state.  The -F option is used
       to indicate type information for the files affected.

         # zfs diff tank/test@before tank/test
         M       /       /tank/test/
         M       F       /tank/test/linked      (+1)
         R       F       /tank/test/oldname -> /tank/test/newname
         -       F       /tank/test/deleted
         +       F       /tank/test/created
         M       F       /tank/test/modified

SEE ALSO
     chmod(2), fsync(2), exports(5), fstab(5), rc.conf(5), jail(8), mount(8),
     umount(8), zpool(8)

AUTHORS
     This manual page is a mdoc(7) reimplementation of the OpenSolaris manual
     page zfs(1M), modified and customized for FreeBSD and licensed under the
     Common Development and Distribution License (CDDL).

     The mdoc(7) implementation of this manual page was initially written by
     Martin Matuska <mm@FreeBSD.org>.

FreeBSD 11.0-PRERELEASE         April 23, 2014         FreeBSD 11.0-PRERELEASE

NAME | SYNOPSIS | DESCRIPTION | SUBCOMMANDS | EXIT STATUS | EXAMPLES | SEE ALSO | AUTHORS

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