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zfs(1M)			System Administration Commands		       zfs(1M)

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 [-rRf] filesystem|volume|snapshot

       zfs snapshot [-r] filesystem@snapname|volume@snapname

       zfs rollback [-rRf] snapshot

       zfs clone [-p] snapshot filesystem|volume

       zfs promote clone-filesystem

       zfs rename filesystem|volume|snapshot
	   filesystem|volume|snapshot

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

       zfs rename -r snapshot snapshot

       zfs list	[-rH] [-o property[,...]] [-t type[,...]]
	   [-s property] ... [-S property ... [filesystem|volume|snapshot] ...

       zfs set property=value filesystem|volume	...

       zfs get [-rHp] [-o field[,...]] [-s source[,...]] "all" | property[,...]
	    filesystem|volume|snapshot ...

       zfs inherit [-r]	property filesystem|volume ...

       zfs upgrade [-v]

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

       zfs mount

       zfs mount [-vO] [-o options] -a | filesystem

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

       zfs share -a | filesystem

       zfs unshare  -a filesystem|mountpoint

       zfs send	[-vR] [-[-iI] snapshot]	snapshot

       zfs receive [-vnF] filesystem|volume|snapshot

       zfs receive [-vnF] -d filesystem

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

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

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

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

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

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

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

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

       zfs jail	jailid filesystem

       zfs unjail jailid filesystem

DESCRIPTION
       The  zfs	 command configures ZFS	datasets within	a ZFS storage pool, as
       described in zpool(1M). 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	 standard  POSIX  file system. ZFS file	systems	can be
		      mounted within the standard file	system	namespace  and
		      behave like any other file system.

       volume	      A	logical	volume exported	as a raw or block device. This
		      type of dataset should only be used under	 special  cir-
		      cumstances.  File	 systems  are  typically  used in most
		      environments. Volumes cannot be  used  in	 a  non-global
		      zone.

       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(1M) command.

       See zpool(1M) 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"	direc-
       tory  in	 the  root  of	the  file  system. Snapshots are automatically
       mounted on demand and may be unmounted at regular intervals. The	 visi-
       bility of the ".zfs" directory can be controlled	by the "snapdir" prop-
       erty.

   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/vfstab file. All automatically managed file sys-
       tems 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" prop-
       erty. This directory is created as needed, and ZFS automatically	mounts
       the file	system when the	"zfs mount -a"	command	 is  invoked  (without
       editing	/etc/vfstab).  The mountpoint property can be inherited, so if
       pool/home has a mount point of /export/stuff, then pool/home/user auto-
       matically inherits a mount point	of /export/stuff/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,	umount,	/etc/vfstab). 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 sys-
       tem.

   Zones
       A ZFS file system can be	added to a non-global zone by using  zonecfg's
       "add  fs"  subcommand.  A ZFS file system that is added to a non-global
       zone must have its mountpoint property set to legacy.

       The physical properties of an added file	system are controlled  by  the
       global  administrator. However, the zone	administrator can create, mod-
       ify, or destroy files within the	added file system,  depending  on  how
       the file	system is mounted.

       A dataset can also be delegated to a non-global zone by using zonecfg's
       "add dataset" subcommand. You cannot delegate a dataset to one zone and
       the  children of	the same dataset to another zone. The zone administra-
       tor can change properties of the	dataset	or any of its  children.  How-
       ever, the "quota" property is controlled	by the global administrator.

       A  ZFS  volume  can  be added as	a device to a non-global zone by using
       zonecfg's "add device" subcommand. However, its physical	properties can
       only be modified	by the global administrator.

       For more	information about zonecfg syntax, see zonecfg(1M).

       After a dataset is delegated to a non-global zone, the "zoned" property
       is automatically	set. A zoned file system  cannot  be  mounted  in  the
       global  zone,  since the	zone administrator might have to set the mount
       point to	an unacceptable	value.

       The global administrator	 can  forcibly	clear  the  "zoned"  property,
       though  this should be done with	extreme	care. The global administrator
       should verify that all the mount	points are acceptable before  clearing
       the property.

   Native Properties
       Properties  are	divided	 into  two  types,  native properties and user
       defined 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.

       Every  dataset has a set	of properties that export statistics about the
       dataset as well as control various behavior. Properties	are  inherited
       from the	parent unless overridden by the	child. Snapshot	properties can
       not be edited; they always inherit their	inheritable properties.	 Prop-
       erties that are not applicable to snapshots are not displayed.

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

	 "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 cannot be set, nor	 are  they  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

	   The compression ratio achieved for this  dataset,  expressed	 as  a
	   multiplier.	Compression  can be turned on by running "zfs set com-
	   pression=on dataset". The default value is "off".

       creation

	   The time this dataset was created.

       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. The origin cannot	be destroyed (even with	the -r
	   or -f options) so long as a clone exists.

       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".

       type

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

       used

	   The	amount	of  space consumed by this dataset and all its descen-
	   dents. 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(3c)  or	O_SYNC does not	necessarily guarantee that the
	   space usage information is updated immediately.

       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".

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

       aclinherit=discard | noallow | restricted | passthrough

	   Controls  how  ACL entries are inherited when files and directories
	   are created.	A file system with an "aclinherit" property  of	 "dis-
	   card"  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"	inher-
	   its	all  inheritable ACL entries without any modifications made to
	   the ACL entries when	they are inherited.

	   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

	   Controls how	an ACL is modified during chmod(2). A file system with
	   an "aclmode"	property of "discard" deletes all ACL entries that  do
	   not	represent  the	mode  of  the  file.  An "aclmode" property of
	   "groupmask" (the default) reduces user or  group  permissions.  The
	   permissions	are  reduced,  such  that they are no greater than the
	   group permission bits, unless it is a user entry that has the  same
	   UID	as  the	 owner of the file or directory. In this case, the ACL
	   permissions are reduced so that they	are no greater than owner per-
	   mission   bits.  A  file  system  with  an  "aclmode"  property  of
	   "passthrough" indicates that	no changes are made to the  ACL	 other
	   than	generating the necessary ACL entries to	represent the new mode
	   of the file or directory.

       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  charac-
	   teristics.

	   When	 the "noauto" option 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 unmount -a" command.

	   This	property is not	inherited.

       checksum=on | off | fletcher2, |	fletcher4 | sha256

	   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. Disabling
	   checksums is	NOT a recommended practice.

       compression=on |	off | lzjb | gzip | gzip-N

	   Controls the	compression  algorithm	used  for  this	 dataset.  The
	   "lzjb"  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)).

	   This	property can also be referred to by its	shortened column  name
	   "compress".

       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=" option.

       devices=on | off

	   Controls whether device nodes can be	opened on  this	 file  system.
	   The default value is	"on".

       exec=on | off

	   Controls  whether  processes	 can be	executed from within this file
	   system. The default value is	"on".

       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.	Other-
	   wise,  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 sys-
	   tems	are unshared and shared	in the new location.

       nbmand=on | off

	   Controls whether the	file system should be  mounted	with  "nbmand"
	   (Non	 Blocking  mandatory  locks).  This  is	used for CIFS clients.
		Changes	to this	property only take effect when the file	system
	   is  umounted	 and  remounted. See mount(1M) for more	information on
	   "nbmand" mounts.

       quota=size | none

	   Limits the amount of	space a	dataset	and its	descendents  can  con-
	   sume.  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.

       readonly=on | off

	   Controls whether this dataset can be	modified. The default value is
	   "off".

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

       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	 data-
	   base	can result in significant performance gains. Use of this prop-
	   erty	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 only  affects	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 descen-
	   dents. 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".

       setuid=on | off

	   Controls  whether the set-UID bit is	respected for the file system.
	   The default value is	"on".

       shareiscsi=on | off

	   Like	the "sharenfs" property, "shareiscsi" indicates	whether	a  ZFS
	   volume  is  exported	 as an iSCSI target. The acceptable values for
	   this	property are "on", "off", and "type=disk".  The	default	 value
	   is "off". In	the future, other target types might be	supported. For
	   example, "tape".

	   You might want to set "shareiscsi=on" for a file system so that all
	   ZFS	volumes	 within	the file system	are shared by default. Setting
	   this	property on a file system has no direct	effect,	however.

       sharesmb=on | off | opts

	   Controls whether the	file system is shared  by  using  the  Solaris
	   CIFS	 service,  and what options are	to be used. A file system with
	   the "sharesmb" property set to "off"	is managed through traditional
	   tools such as sharemgr(1M). Otherwise, the file system is automati-
	   cally shared	and unshared with the "zfs share"  and	"zfs  unshare"
	   commands.  If the property is set to	"on", the sharemgr(1M) command
	   is invoked with no options. Otherwise, the sharemgr(1M) command  is
	   invoked with	options	equivalent to the contents of this property.

	   Because SMB shares requires a resource name,	a unique resource name
	   is constructed from the dataset name. The  constructed  name	 is  a
	   copy	 of the	dataset	name except that the characters	in the dataset
	   name, which would be	illegal	in the	resource  name,	 are  replaced
	   with	 underscore  (_)  characters. A	pseudo property	"name" is also
	   supported that allows you to	replace	the data set name with a spec-
	   ified  name.	 The specified name is then used to replace the	prefix
	   dataset in the case of inheritance. For  example,  if  the  dataset
	   "data/home/john" is set to "name=john", then	"data/home/john" has a
	   resource   name   of	  "john".    If	   a	child	 dataset    of
	   "data/home/john/backups", it	has a resource name of "john_backups".

	   When	the "sharesmb" property	is changed for a dataset, the  dataset
	   and any children inheriting the property are	re-shared with the new
	   options, only if the	property was previously	set to	"off",	or  if
	   they	 were shared before the	property was changed. If the new prop-
	   erty	is set to "off", the file systems are unshared.

       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	through	  traditional	tools	such   as   share(1M),
	   unshare(1M),	and dfstab(4). Otherwise, the file system is automati-
	   cally shared	and unshared with the "zfs share"  and	"zfs  unshare"
	   commands.  If the property is set to	"on", the share(1M) command is
	   invoked with	 no  options.  Otherwise,  the	share(1M)  command  is
	   invoked with	options	equivalent to the contents of this property.

	   When	 the "sharenfs"	property is changed for	a dataset, the dataset
	   and any children inheriting the property are	re-shared with the new
	   options, only if the	property was previously	"off", or if they were
	   shared before the property was changed.  If	the  new  property  is
	   "off", the file systems are unshared.

       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".

       version=1|2|current

	   The	on-disk	 version  of this file system, which is	independent of
	   the pool version. This property can only be set to later  supported
	   versions. See "zfs upgrade".

       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 refreserva-
	   tion	is set instead.	Any changes to volsize	are  reflected	in  an
	   equivalent  change to the reservation (or refreservation). The vol-
	   size	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 pre-
	   vent	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 pro-
	   visioning") 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 reserva-
	   tion	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 reserva-
	   tion.

       vscan=on|off

	   Controls whether regular files should be scanned for	viruses	when a
	   file	 is  opened and	closed.	In addition to enabling	this property,
	   the virus scan service must also be enabled for virus  scanning  to
	   occur. The default value is "off".

       xattr=on	| off

	   Controls whether extended attributes	are enabled for	this file sys-
	   tem.	The default value is "on".

       zoned=on	| off

	   Controls whether the	dataset	is managed from	a non-global zone. See
	   the	"Zones"	 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 cre-
       ated. If	the properties are not set  with  the  "zfs  create"  command,
       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 com-
	   bination 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.  Currently,  case-insensitive
	   matching  behavior on a file	system that supports mixed behavior is
	   limited to the Solaris CIFS server product.	For  more  information
	   about the "mixed" value behavior, see the ZFS Administration	Guide.

       normalization =none | formD | formKCf

	   Indicates whether the file system should perform a unicode  normal-
	   ization  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 can-
	   not be changed after	the file system	is created.

       jailed =on | off

	   Controls whether the	dataset	is managed from	 within	 a  jail.  The
	   default value is "off".

       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(1M)  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
	     devices		     devices/nodevices
	     exec		     exec/noexec
	     readonly		     ro/rw
	     setuid		     setuid/nosetuid
	     xattr		     xattr/noxattr

       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 val-
       ues  specified  on  the	command	line override the values stored	in the
       dataset.	The -nosuid  option  is	 an  alias  for	 "nodevices,nosetuid".
       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.

       User  property  names  must contain a colon (":") character, to distin-
       guish them from native properties. They might  contain  lowercase  let-
       ters,  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 "mod-
       ule: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  sug-
       gested  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  Microsys-
       tems.

       The  values of user properties are arbitrary strings, are always	inher-
       ited, and are never validated. All of  the  commands  that  operate  on
       properties  ("zfs  list",  "zfs	get",  "zfs set", etc.)	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.

   Volumes as Swap or Dump Devices
       To  set up a swap area, create a	ZFS volume of a	specific size and then
       enable swap on that device. For more information, see the EXAMPLES sec-
       tion.

       Do  not swap to a file on a ZFS file system. A ZFS swap file configura-
       tion is not supported.

       Using a ZFS volume as a dump device is not supported.

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  automati-
				cally  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 com-
				pletes successfully.

	   -o property=value	Sets the specified property  as	 if  "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/{dsk,rdsk}/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 automati-
				cally 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  com-
				pletes successfully.

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

	   -o property=value	Sets  the  specified  property	as if "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.

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

       zfs destroy [-rRf] filesystem|volume|snapshot

	   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, snapshots, clones).

	   -r	 Recursively destroy all children. If a	snapshot is specified,
		 destroy all snapshots with this name in descendent file  sys-
		 tems.

	   -R	 Recursively  destroy  all  dependents,	 including cloned file
		 systems outside the target hierarchy. If a snapshot is	speci-
		 fied, destroy all snapshots with this name in descendent file
		 systems.

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

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

       zfs snapshot [-r] filesystem@snapname|volume@snapname

	   Creates a snapshot with the given name. See the "Snapshots" section
	   for details.

	   -r	 Recursively  create  snapshots	 of  all  descendent datasets.
		 Snapshots are taken atomically, so that all  recursive	 snap-
		 shots correspond to the same moment in	time.

       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	 snap-
	   shot	 other than the	most recent one. In order to do	so, all	inter-
	   mediate snapshots must be destroyed by specifying the -r option.

	   -r	 Recursively destroy any snapshots more	recent	than  the  one
		 specified.

	   -R	 Recursively destroy any more recent snapshots,	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] 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 cre-
		 ated 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.

       zfs promote clone-filesystem

	   Promotes a clone file system	to no longer be	dependent on its "ori-
	   gin"	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 snap-
	   shot	 names	of  its	 own.  The  "rename" subcommand	can be used to
	   rename any conflicting snapshots.

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

	   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 non-existing parent datasets.	Datasets  cre-
		 ated  in  this	 manner	are automatically mounted according to
		 the "mountpoint" property inherited from their	parent.

       zfs rename -r snapshot snapshot

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

       zfs list	[-rH] [-o property[,...]] [ -t 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 abso-
	   lute	pathname or the	relative pathname. By  default,	 all  datasets
	   are displayed and contain the following fields:

	     name,used,available,referenced,mountpoint

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

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

	   -o property	  A comma-separated list of properties to display. The
			  property  must be one	of the properties described in
			  the "Native  Properties"  section,  or  the  special
			  value	"name" to display the dataset name.

	   -s property	  A  property  to use for sorting the output by	column
			  in ascending order based on the value	of  the	 prop-
			  erty.	 The  property	must  be one of	the properties
			  described in the "Properties"	section, or  the  spe-
			  cial	value "name" to	sort by	the dataset name. Mul-
			  tiple	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 pre-
				     served.

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

	   -t type	  A  comma-separated  list  of types to	display, where
			  "type" is one	of "filesystem", "snapshot"  or	 "vol-
			  ume".	For example, specifying	"-t snapshot" displays
			  only snapshots.

       zfs set property=value filesystem|volume	...

	   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,  Kbytes, Mbytes, gigabytes, terabytes, petabytes,
	   exabytes, or	zettabytes, respectively). Properties cannot be	set on
	   snapshots.

       zfs get [-rHp] [-o field[,...] [-s source[,...] "all" | 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 are displayed by	default, though	this can be controlled
	   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  for
	   the given dataset.

	   -r		Recursively display properties for any 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.

	   -o field	A  comma-separated  list  of   columns	 to   display.
			"name,property,value,source" is	the default value.

	   -s 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,none".
			The default value is all sources.

	   -p		Display	numbers	in parsable (exact) values.

       zfs inherit [-r]	property filesystem|volume ...

	   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.

       zfs upgrade [-v]

	   Displays a list of file systems that	are not	the most  recent  ver-
	   sion.

       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 can not be accessed on  systems
	   running older versions of the software.

	   The	file  system  version  is independent of the pool version (see
	   zpool(1M) for information on	the "zpool upgrade" command).

	   The file system version does	not have to be upgraded	when the  pool
	   version is upgraded,	and vice versa.

	   -a		 Upgrade all file systems on all imported pools.

	   filesystem	 Upgrade the specified file system.

	   -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.

       zfs mount

	   Displays all	ZFS file systems currently mounted.

       zfs mount [-vO] [-o options] -a | filesystem

	   Mounts ZFS file systems. Invoked automatically as part of the  boot
	   process.

	   -o options	 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.

	   -O		 Perform an overlay  mount.  See  mount(1M)  for  more
			 information.

	   -v		 Report	mount progress.

	   -a		 Mount	all  available ZFS file	systems. Invoked auto-
			 matically as part of the boot process.

	   filesystem	 Mount the specified filesystem.

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

	   Unmounts currently mounted ZFS file systems.	Invoked	 automatically
	   as part of the shutdown process.

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

	   -a			    Unmount all	available  ZFS	file  systems.
				    Invoked  automatically as part of the boot
				    process.

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

       zfs share -a | filesystem

	   Shares available ZFS	file systems.

	   -a		 Share all available ZFS file systems.	Invoked	 auto-
			 matically as part of the boot process.

	   filesystem	 Share	the  specified	filesystem  according  to  the
			 "sharenfs" and	"sharesmb"  properties.	 File  systems
			 are shared when the "sharenfs"	or "sharesmb" property
			 is set.

       zfs unshare -a |	filesystem|mountpoint

	   Unshares currently shared ZFS file systems. This is	invoked	 auto-
	   matically as	part of	the shutdown process.

	   -a			    Unshare  all  available  ZFS file systems.
				    Invoked automatically as part of the  boot
				    process.

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

       zfs send	[-vR] [-[-iI] snapshot]	snapshot

	   Creates  a  stream  representation of the second snapshot, 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	 snap-
			  shot	to the second snapshot.	The incremental	source
			  (the first snapshot) can be specified	 as  the  last
			  component  of	 the  snapshot	name (for example, the
			  part after the "@"), and it is assumed  to  be  from
			  the same file	system as the second snapshot.

			  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 intermedi-
			  ary 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  incremen-
			  tal  source snapshot may be specified	as with	the -i
			  option.

	   -R		  Generate a replication stream	 package,  which  will
			  replicate  the specified filesystem, and all descen-
			  dant 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  recieved, snapshots and file
			  systems that do not exist on the  sending  side  are
			  destroyed.

	   -v		  Print	 verbose  information about the	stream package
			  generated.

	   The format of the stream is evolving. No backwards compatibility is
	   guaranteed.	You  may not be	able to	receive	your streams on	future
	   versions of ZFS.

       zfs receive [-vnF] filesystem|volume|snapshot
       zfs receive [-vnF] -d 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 re-created,	which means the	zvol cannot be
	   accessed during the receive operation.

	   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 option.

	   If the argument is a	snapshot name, the specified snapshot is  cre-
	   ated.  If  the argument is a	file system or volume name, a snapshot
	   with	the same name as the sent snapshot is created within the spec-
	   ified  filesystem  or  volume.   If the -d 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, any
	   required file systems within	the specified one are created.

	   -d	 Use the name of the sent snapshot to determine	 the  name  of
		 the new snapshot as described in the paragraph	above.

	   -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	 snap-
		 shot before performing	the receive operation. If receiving an
		 incremental replication stream	(for example, one generated by
		 "zfs send -R -[iI]"), destroy snapshots and file systems that
		 do not	exist on the sending side.

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

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

	   [-ug] "everyone"|user|group[,...]

	       Specifies to whom the permissions are delegated.	Multiple enti-
	       ties  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 options.

	   [-e]	perm|@setname[,...]

	       Specifies that the permissions be delegated to "everyone." Mul-
	       tiple  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  permis-
	       sions 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 the 'mount' ability in the origin
				   file	system.
	 create	      subcommand   Must	also have the 'mount' ability.
	 destroy      subcommand   Must	also have the 'mount' ability.
	 mount	      subcommand   Allows mount, unmount, and
				   create/remove zvol device links.
	 promote      subcommand   Must	also have the 'mount' ability and
				   'promote' ability in	the origin file	system.
	 receive      subcommand   Must	also have the 'mount' ability and
				   the 'create'	ability.
	 rename	      subcommand   Must	also have the 'mount' ability and
				   the 'create'	ability	in the new parent.
	 rollback     subcommand   Must	also have the 'mount' ability.
	 snapshot     subcommand   Must	also have the 'mount' ability.
	 share	      subcommand   Allows share	and unshare.
	 send	      subcommand

	 aclinherit   property
	 aclmode      property
	 atime	      property
	 canmount     property
	 checksum     property
	 compression  property
	 copies	      property
	 devices      property
	 exec	      property
	 mountpoint   property
	 quota	      property
	 readonly     property
	 recordsize   property
	 reservation  property
	 setuid	      property
	 shareiscsi   property
	 sharenfs     property
	 snapdir      property
	 version      property
	 volsize      property
	 xattr	      property
	 zoned	      property
	 userprop     other	   Allows changing any user property.

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

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

       zfs allow -s @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 nam-
	   ing 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] "everyone"|user|group[,...]	[perm|@setname[, ...]]
       filesystem|volume
       zfs unallow [-rld] -e [perm|@setname [,...]] filesystem|volume
       zfs unallow [-r]	-c [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[,...]]
       filesystem|volume

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

       zfs jail	jailid filesystem

	   Attaches  the given file system to the given	jail. 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, sysctl secu-
	   rity.jail.enforce_statfs should  be	set  to	 0  and	 sysctl	 secu-
	   rity.jail.mount_allowed should be set to 1.

       zfs unjail jailid filesystem

	   Detaches the	given file system from the given jail.

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  "/export/home"  is
       set  for	 the  parent  file  system, and	automatically inherited	by the
       child file system.

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

       Example 2 Creating a ZFS	Snapshot

       The following command creates a snapshot	named "yesterday". This	 snap-
       shot  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 Taking	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 Turning Off Compression

       The  following commands turn compression	off for	all file systems under
       "pool/home", but	explicitly turns it on 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.

	 # zfs list

	   NAME			     USED  AVAIL  REFER	 MOUNTPOINT
	   pool			     450K   457G    18K	 /pool
	   pool/home		     315K   457G    21K	 /export/home
	   pool/home/anne	      18K   457G    18K	 /export/home/anne
	   pool/home/bob	     276K   457G   276K	 /export/home/bob
	   pool/home/bob@yesterday	0      -   276K	 -

       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	 Thu Jul 12 14:44 2007	-
	   pool/home/bob  used		 276K			-
	   pool/home/bob  available	 50.0G			-
	   pool/home/bob  referenced	 276K			-
	   pool/home/bob  compressratio	 1.00x			-
	   pool/home/bob  mounted	 yes			-
	   pool/home/bob  quota		 50G			local
	   pool/home/bob  reservation	 none			default
	   pool/home/bob  recordsize	 128K			default
	   pool/home/bob  mountpoint	 /export/home/bob	inherited from
								pool/home
	   pool/home/bob  checksum	 on			default
	   pool/home/bob  compression	 off			default
	   pool/home/bob  atime		 on			default
	   pool/home/bob  devices	 on			default
	   pool/home/bob  exec		 on			default
	   pool/home/bob  setuid	 on			default
	   pool/home/bob  readonly	 off			default
	   pool/home/bob  zoned		 off			default
	   pool/home/bob  snapdir	 hidden			default
	   pool/home/bob  aclmode	 groupmask		default
	   pool/home/bob  aclinherit	 restricted		default
	   pool/home/bob  canmount	 on			default
	   pool/home/bob  nbmand	 off			default
	   pool/home/bob  shareiscsi	 off			default
	   pool/home/bob  sharesmb	 off			default
	   pool/home/bob  sharenfs	 off			default
	   pool/home/bob  xattr		 on			default
	   pool/home/bob  refquota	 10M			local
	   pool/home/bob  refreservation none			default
	   pool/home/bob  copies	 1			default
	   pool/home/bob  version	 1			-

       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 -r -s local -o name,property,value all pool/home/bob

	   NAME		    PROPERTY	  VALUE
	   pool		    compression	  on
	   pool/home	    checksum	  off

       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 con-
       tents 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
	 # zfs snapshot	pool/project/production@today
	 # zfs clone pool/project/production@today pool/project/beta
	  make changes to /pool/project/beta and test them
	 # 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  sys-
       tem  "poolB/received". If "poolB/received/fsA" does not exist, it is be
       created as an empty file	system.

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

       Example 14 Creating a ZFS volume	as a Swap Device

       The following example shows how to create a 5-Gbyte ZFS volume and then
       add the volume as a swap	device.

	 # zfs create -V 5gb tank/vol
	 # swap	-a /dev/zvol/dsk/tank/vol

       Example 15 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 16 Creating a ZFS Volume	as a iSCSI Target Device

       The following example shows how to create a ZFS volume as an iSCSI tar-
       get.

	 # zfs create -V 2g pool/volumes/vol1
	 # zfs set shareiscsi=on pool/volumes/vol1
	 # iscsitadm list target
	 Target: pool/volumes/vol1
	 iSCSI Name:
	 iqn.1986-03.com.sun:02:7b4b02a6-3277-eb1b-e686-a24762c52a8c
	 Connections: 0

       After the iSCSI target is created, set up the iSCSI initiator. For more
       information about the Solaris iSCSI initiator, see the Solaris Adminis-
       tration Guide: Devices and File Systems.

       Example 17 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@yesterday @2daysago
	 # zfs rename -r pool/users@today @yesterday
	 # zfs snapshot	-r pool/users@today

       Example 18 Setting sharenfs Property Options on a ZFS File System

       The following commands show how to set "sharenfs" property  options  to
       enable  rw  access  for a set of	IP addresses and to enable root	access
       for system neo on the tank/home file system.

	 # zfs set sharenfs='rw=@123.123.0.0/16,root=neo' tank/home

       If you are using	DNS for	host name resolution, specify the fully	quali-
       fied hostname.

       Example 19 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
	 -------------------------------------------------------------

       Because	the  tank/cindys  mount	 point	permission  is	set  to	755 by
       default,	user cindys  will  be  unable  to  mount  file	systems	 under
       tank/cindys.  Set  an  ACL  similar  to the following syntax to provide
       mount point access:

	 # chmod A+user:cindys:add_subdirectory:allow /tank/cindys

       Example 20 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 mem-
       bers 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 21 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 dis-
       played.

	 # 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 22 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 users/home
	 -------------------------------------------------------------
	 Local+Descendent permissions on (users/home)
		user cindys quota,reservation
	 -------------------------------------------------------------
	 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 23 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
	 -------------------------------------------------------------

EXIT STATUS
       The following exit values are returned:

       0    Successful completion.

       1    An error occurred.

       2    Invalid command line options were specified.

ATTRIBUTES
       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE	TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Availability		     |SUNWzfsu			   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Committed			   |
       +-----------------------------+-----------------------------+

SEE ALSO
       gzip(1),	  ssh(1),  mount(1M),  share(1M),  sharemgr(1M),  unshare(1M),
       zonecfg(1M),  zpool(1M),	 chmod(2),  stat(2),   fsync(3c),   dfstab(4),
       attributes(5)

       For information about using the ZFS web-based management	tool and other
       ZFS features, see the ZFS Administration	Guide.

SunOS 5.11			  8 Apr	2008			       zfs(1M)

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

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