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GLABEL(8) FreeBSD 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 refresh 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 GEOM 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 disk ID strings are exported as labels in the format /dev/diskid/GEOM_CLASS-ident e.g. /dev/diskid/DISK-6QG3Z026. Generic labels created and managed solely by glabel(8) are created in the /dev/label/ directory. Note that for all label types, nested GEOM classes will cause additional device nodes to be created, with context-specific data appended to their names. E.g. for every node like /dev/label/bigdisk there will be additional entries for any partitions which the device contains, like /dev/label/bigdiskp1 and /dev/label/bigdiskp1a. The first argument to glabel indicates an action to be performed: 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. refresh Refresh / rediscover metadata from 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. kern.geom.label.*.enable: 1 Most LABEL providers implement a sysctl(8) flag and a tunable variable named in the above format. This flag controls if the label provider will be active, tasting devices and creating label nodes in the devfs(5) tree. It is sometimes desirable to disable certain label types if they conflict with other classes in complex GEOM topologies. 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 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 14.0-RELEASE-p11 March 12, 2017 FreeBSD 14.0-RELEASE-p11