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gnop(8) [freebsd man page]

GNOP(8) 						    BSD System Manager's Manual 						   GNOP(8)

NAME
gnop -- control utility for NOP GEOM class SYNOPSIS
gnop create [-v] [-e error] [-o offset] [-r rfailprob] [-s size] [-S secsize] [-w wfailprob] dev ... gnop configure [-v] [-e error] [-r rfailprob] [-w wfailprob] prov ... gnop destroy [-fv] prov ... gnop reset [-v] prov ... gnop list gnop status gnop load gnop unload DESCRIPTION
The gnop utility is used for setting up transparent providers on existing ones. Its main purpose is testing other GEOM classes, as it allows forced provider removal and I/O error simulation with a given probability. It also gathers the following statistics: number of read requests, number of write requests, number of bytes read and number of bytes written. In addition, it can be used as a good starting point for implementing new GEOM classes. The first argument to gnop indicates an action to be performed: create Set up a transparent provider on the given devices. If the operation succeeds, the new provider should appear with name /dev/<dev>.nop. The kernel module geom_nop.ko will be loaded if it is not loaded already. configure Configure existing transparent provider. At the moment it is only used for changing failure probability. destroy Turn off the given transparent providers. reset Reset statistics for the given transparent providers. list See geom(8). status See geom(8). load See geom(8). unload See geom(8). Additional options: -e error Specifies the error number to return on failure. -f Force the removal of the specified provider. -o offset Where to begin on the original provider. -r rfailprob Specifies read failure probability in percent. -s size Size of the transparent provider. -S secsize Sector size of the transparent provider. -w wfailprob Specifies write failure probability in percent. -v Be more verbose. SYSCTL VARIABLES
The following sysctl(8) variables can be used to control the behavior of the NOP GEOM class. The default value is shown next to each vari- able. kern.geom.nop.debug: 0 Debug level of the NOP GEOM class. This can be set to a number between 0 and 2 inclusive. If set to 0, minimal debug information is printed. If set to 1, basic debug information is logged along with the I/O requests that were returned as errors. If set to 2, the maximum amount of debug information is printed including all I/O requests. EXIT STATUS
Exit status is 0 on success, and 1 if the command fails. EXAMPLES
The following example shows how to create a transparent provider for disk /dev/da0 with 50% write failure probability, and how to destroy it. gnop create -v -w 50 da0 gnop destroy -v da0.nop The traffic statistics for the given transparent providers can be obtained with the list command. The example below shows the number of bytes written with newfs(8): gnop create da0 newfs /dev/da0.nop gnop list SEE ALSO
geom(4), geom(8) HISTORY
The gnop utility appeared in FreeBSD 5.3. AUTHORS
Pawel Jakub Dawidek <pjd@FreeBSD.org> BSD
April 14, 2013 BSD

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GLABEL(8)						    BSD 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 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: 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 vari- able. 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 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> BSD
April 22, 2013 BSD
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