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

     glabel - disk labelization control utility

     glabel create [-v] name dev
     glabel destroy [-fv] name [name [...]]
     glabel label [-v] name dev
     glabel stop [-fv] name [name [...]]
     glabel clear [-v] dev [dev [...]]
     glabel dump dev [dev [...]]
     glabel list [prov [...]]
     glabel load [-v]
     glabel unload [-v]

     The glabel utility is used for GEOM providers labelization.  A label can
     be set up on a GEOM provider in two ways: ``manual'' or ``automatic''.
     When using the ``manual'' method, no metadata are stored on the devices,
     so a label has to be configured by hand every time it is needed.  The
     ``automatic'' method uses on-disk metadata to store the label and detect
     it automatically in the future.

     This class also provides volume label detection for file systems.  Those
     labels cannot be set with glabel, but must be set with the appropriate
     file system utility, e.g. for UFS the file system label is set with
     tunefs(8).  Currently supported file systems are:

           +o   UFS1 (directory /dev/ufs/).
           +o   UFS2 (directory /dev/ufs/).
           +o   MSDOSFS (FAT12, FAT16, FAT32) (directory /dev/msdosfs/).
           +o   CD ISO9660 (directory /dev/iso9660/).

     Non file-system labels are created in the directory /dev/label/.

     The first argument to glabel indicates an action to be performed:

     create       Create temporary label name for the given provider.  This is
                  the ``manual'' method.  The kernel module geom_label.ko will
                  be loaded if it is not loaded already.

     label        Set up a label name for the given provider.  This is the
                  ``automatic'' method, where metadata is stored in provider's
                  last sector.  The kernel module geom_label.ko will be loaded
                  if it is not loaded already.

     stop         Turn off the given label by its name.  This command does not
                  touch on-disk metadata!

     destroy      Same as stop.

     clear        Clear metadata on the given devices.

     dump         Dump metadata stored on the given devices.

     list         List all currently configured devices, or list the given

     load         Load geom_label.ko kernel module.

     unload       Unload geom_label.ko kernel module.

     Additional options:

     -f      Force the removal of the specified labels.

     -v      Be more verbose.

     The following sysctl(8) variables can be used to control the behavior of
     the LABEL GEOM class.  The default value is shown next to each variable.

     kern.geom.label.debug: 0
             Debug level of the LABEL GEOM class.  This can be set to a number
             between 0 and 2, both included.  If set to 0 minimal debug
             information is printed, and if set to 2 the maximum amount of
             debug information in printed.

     The following example shows how to set up a label for disk ``da2'',
     create a file system on it, and mount it:

           glabel label -v usr /dev/da2
           newfs /dev/label/usr
           mount /dev/label/usr /usr
           umount /usr
           glabel stop usr
           glabel unload

     The next example shows how to set up a label for a UFS file system:

           tunefs -L data /dev/da4s1a
           mount /dev/ufs/data /mnt/data

     Exit status is 0 on success, and 1 if the command fails.

     geom(4), loader.conf(5), geom(8), mount(8), newfs(8), sysctl(8),
     tunefs(8), umount(8)

     The glabel utility appeared in FreeBSD 5.3.

     Pawel Jakub Dawidek <>

FreeBSD 11.0-PRERELEASE          July 2, 2004          FreeBSD 11.0-PRERELEASE


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