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

NAME
     gnop -- control utility for NOP GEOM class

SYNOPSIS
     gnop create [-v] [-f failprob] [-o	offset]	[-s size] [-S secsize] dev1
	  [dev2	[...]]
     gnop configure [-v] [-f failprob] prov1 [prov2 [...]]
     gnop destroy [-fv]	prov1 [prov2 [...]]
     gnop list [prov [...]]
     gnop load [-v]
     gnop unload [-v]

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 force
     providers removal and I/O errors simulation with a	given probability.  It
     is	also 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	opera-
		tion succeded, 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.  The kernel	module
		geom_nop.ko will be loaded if it is not	loaded already.

     destroy	Turn off the given transparent providers.

     list	List all or the	given currently	configured providers.

     load	Load geom_nop.ko kernel	module.

     unload	Unload geom_nop.ko kernel module.

     Additional	options:

     -f		  Force	the removal of the specified provider.

     -f	failprob  Specifies failure probability	in percentage.

     -o	offset	  Where	to begin on the	original provider.

     -s	size	  Size of the transparent provider.

     -S	secsize	  Sector size of the transparent provider.

     -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 variable.

     kern.geom.nop.debug: 0
	     Debug level of the	NOP GEOM class.	 This can be set to a number
	     between 0 and 2, both included.  If set to	0 minimal debug	infor-
	     mation is printed,	and if set to 2	the maximum amount of debug
	     information in printed.

EXAMPLES
     The following example shows how to	create a transparent provider for disk
     /dev/da0 with 50% failure probability and destroy it.

	   gnop	create -v -f 50	da0
	   gnop	destroy	-v da0.nop

DIAGNOSTICS
     Exit status is 0 on success, and 1	if the command fails.

SEE ALSO
     geom(4), geom(8)

HISTORY
     The gnop utility appeared in FreeBSD 5.3.

AUTHORS
     Pawel Jakub Dawidek <pjd@FreeBSD.org>

FreeBSD	9.3			 May 21, 2004			   FreeBSD 9.3

NAME | SYNOPSIS | DESCRIPTION | SYSCTL VARIABLES | EXAMPLES | DIAGNOSTICS | SEE ALSO | HISTORY | AUTHORS

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