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

     The glabel utility is used for GEOM provider 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/).
           +o   EXT2FS (directory /dev/ext2fs/).
           +o   REISERFS (directory /dev/reiserfs/).
           +o   NTFS (directory /dev/ntfs/).

     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 a 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     See geom(8).

     status   See geom(8).

     load     See geom(8).

     unload   See geom(8).

     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 inclusive.  If set to 0 minimal debug information
             is printed, and if set to 2 the maximum amount of debug informa-
             tion is printed.

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

     The following example shows how to set up a label for disk ``da2'', cre-
     ate 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

     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 6.2                      July 2, 2004                      FreeBSD 6.2


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