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

NAME
     glabel -- disk labelization control utility

SYNOPSIS
     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

DESCRIPTION
     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:

	   *   UFS1 volume names (directory /dev/ufs/).
	   *   UFS2 volume names (directory /dev/ufs/).
	   *   UFS1 file system IDs (directory /dev/ufsid/).
	   *   UFS2 file system IDs (directory /dev/ufsid/).
	   *   MSDOSFS (FAT12, FAT16, FAT32) (directory /dev/msdosfs/).
	   *   CD ISO9660 (directory /dev/iso9660/).
	   *   EXT2FS (directory /dev/ext2fs/).
	   *   REISERFS (directory /dev/reiserfs/).
	   *   NTFS (directory /dev/ntfs/).

     Support for partition metadata is implemented for:

	   *   GPT labels (directory /dev/gpt/).
	   *   GPT UUIDs (directory /dev/gptid/).

     Generic 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.

SYSCTL VARIABLES
     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 information
	     is printed.

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

EXAMPLES
     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

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

HISTORY
     The glabel utility appeared in FreeBSD 5.3.

AUTHORS
     Pawel Jakub Dawidek <pjd@FreeBSD.org>

FreeBSD 9.0			  June 13, 2009 		       GLABEL(8)
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