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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 volume names (directory /dev/ufs/).
	   +o   UFS2 volume names (directory /dev/ufs/).
	   +o   UFS1 file system	IDs (directory /dev/ufsid/).
	   +o   UFS2 file system	IDs (directory /dev/ufsid/).
	   +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/).

     Support for partition metadata is implemented for:

	   +o   GPT labels (directory /dev/gpt/).
	   +o   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.

     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	8.1			 June 13, 2009			   FreeBSD 8.1


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