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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GCONCAT(8) BSD System Manager's Manual GCONCAT(8) NAME
gconcat -- disk concatenation control utility SYNOPSIS
gconcat create [-v] name prov ... gconcat destroy [-fv] name ... gconcat label [-hv] name prov ... gconcat stop [-fv] name ... gconcat clear [-v] prov ... gconcat dump prov ... gconcat list gconcat status gconcat load gconcat unload DESCRIPTION
The gconcat utility is used for device concatenation configuration. The concatenation can be configured using two different methods: ``manual'' or ``automatic''. When using the ``manual'' method, no metadata are stored on the devices, so the concatenated device has to be configured by hand every time it is needed. The ``automatic'' method uses on-disk metadata to detect devices. Once devices are labeled, they will be automatically detected and configured. The first argument to gconcat indicates an action to be performed: create Concatenate the given devices with specified name. This is the ``manual'' method. The kernel module geom_concat.ko will be loaded if it is not loaded already. label Concatenate the given devices with the specified name. This is the ``automatic'' method, where metadata are stored in every device's last sector. The kernel module geom_concat.ko will be loaded if it is not loaded already. stop Turn off existing concatenate device 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 concatenated device. -h Hardcode providers' names in metadata. -v Be more verbose. SYSCTL VARIABLES
The following sysctl(8) variables can be used to control the behavior of the CONCAT GEOM class. The default value is shown next to each variable. kern.geom.concat.debug: 0 Debug level of the CONCAT GEOM class. This can be set to a number between 0 and 3 inclusive. If set to 0 minimal debug information is printed, and if set to 3 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 configure four disks for automatic concatenation, create a file system on it, and mount it: gconcat label -v data /dev/da0 /dev/da1 /dev/da2 /dev/da3 newfs /dev/concat/data mount /dev/concat/data /mnt [...] umount /mnt gconcat stop data gconcat unload Configure concatenated provider on one disk only. Create file system. Add two more disks and extend existing file system. gconcat label data /dev/da0 newfs /dev/concat/data gconcat label data /dev/da0 /dev/da1 /dev/da2 growfs /dev/concat/data SEE ALSO
geom(4), loader.conf(5), geom(8), growfs(8), gvinum(8), mount(8), newfs(8), sysctl(8), umount(8) HISTORY
The gconcat utility appeared in FreeBSD 5.3. AUTHORS
Pawel Jakub Dawidek <pjd@FreeBSD.org> BSD
May 21, 2004 BSD