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

NAME
gmountver -- control utility for disk mount verification GEOM class SYNOPSIS
gmountver create [-v] dev ... gmountver destroy [-fv] prov ... gmountver list gmountver status [-s name] gmountver load [-v] gmountver unload [-v] DESCRIPTION
The gmountver utility is used to control the mount verification GEOM class. When configured, it passes all the I/O requests to the underly- ing provider. When the underlying provider disappears - for example because the disk device got disconnected - it queues all the I/O requests and waits for the provider to reappear. When that happens, it attaches to it and sends the queued requests. The first argument to gmountver indicates an action to be performed: create Cache the given devices with specified name. The kernel module geom_mountver.ko will be loaded if it is not loaded already. destroy Destroy name. 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 mountver device. -v Be more verbose. SYSCTL VARIABLES
The following sysctl(8) variables can be used to control the behavior of the MOUNTVER GEOM class. The default value is shown next to each variable. kern.geom.mountver.debug: 0 Debug level of the MOUNTVER GEOM class. This can be set to a number between 0 and 3 inclusive. If set to 0 minimal debug informa- tion is printed, and if set to 3 the maximum amount of debug information is printed. kern.geom.mountver.check_ident: 1 This can be set to 0 or 1. If set to 0, gmountver will reattach to the device even if the device reports a different disk ID. EXIT STATUS
Exit status is 0 on success, and 1 if the command fails. SEE ALSO
geom(4), geom(8) HISTORY
The gmountver utility appeared in FreeBSD 9.0. AUTHORS
Edward Tomasz Napierala <trasz@FreeBSD.org> BSD
January 27, 2015 BSD
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