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ZTEST(1)		FreeBSD	General	Commands Manual		      ZTEST(1)

NAME
     ztest -- was written by the ZFS Developers	as a ZFS unit test

SYNOPSIS
     ztest [-VEG] [-v vdevs] [-s size_of_each_vdev] [-a	alignment_shift]
	   [-m mirror_copies] [-r raidz_disks/draid_disks] [-R raid_parity]
	   [-K raid_kind] [-D draid_data] [-S draid_spares]
	   [-C vdev_class_state] [-d datasets] [-t threads]
	   [-g gang_block_threshold] [-i initialize_pool_i_times]
	   [-k kill_percentage]	[-p pool_name] [-T time] [-z zil_failure_rate]

DESCRIPTION
     ztest was written by the ZFS Developers as	a ZFS unit test.  The tool was
     developed in tandem with the ZFS functionality and	was executed nightly
     as	one of the many	regression test	against	the daily build.  As features
     were added	to ZFS,	unit tests were	also added to ztest.  In addition, a
     separate test development team wrote and executed more functional and
     stress tests.

     By	default	ztest runs for ten minutes and uses block files	(stored	in
     /tmp) to create pools rather than using physical disks.  Block files af-
     ford ztest	its flexibility	to play	around with zpool components without
     requiring large hardware configurations.  However,	storing	the block
     files in /tmp may not work	for you	if you have a small tmp	directory.

     By	default	is non-verbose.	 This is why entering the command above	will
     result in ztest quietly executing for 5 minutes.  The -V option can be
     used to increase the verbosity of the tool.  Adding multiple -V options
     is	allowed	and the	more you add the more chatty ztest becomes.

     After the ztest run completes, you	should notice many ztest.* files lying
     around.  Once the run completes you can safely remove these files.	 Note
     that you shouldn't	remove these files during a run.  You can re-use these
     files in your next	ztest run by using the -E option.

OPTIONS
     -h, -?, --help
	   Print a help	summary.

     -v, --vdevs= (default: 5)
	   Number of vdevs.

     -s, --vdev-size= (default:	64M)
	   Size	of each	vdev.

     -a, --alignment-shift= (default: 9) (use 0	for random)
	   Alignment shift used	in test.

     -m, --mirror-copies= (default: 2)
	   Number of mirror copies.

     -r, --raid-disks= (default: 4 for raidz/16	for draid)
	   Number of raidz/draid disks.

     -R, --raid-parity=	(default: 1)
	   Raid	parity (raidz &	draid).

     -K, --raid-kind=raidz|draid|random	(default: random)
	   The kind of RAID config to use.  With random	the kind alternates
	   between raidz and draid.

     -D, --draid-data= (default: 4)
	   Number of data disks	in a dRAID redundancy group.

     -S, --draid-spares= (default: 1)
	   Number of dRAID distributed spare disks.

     -d, --datasets= (default: 7)
	   Number of datasets.

     -t, --threads= (default: 23)
	   Number of threads.

     -g, --gang-block-threshold= (default: 32K)
	   Gang	block threshold.

     -i, --init-count= (default: 1)
	   Number of pool initializations.

     -k, --kill-percentage= (default: 70%)
	   Kill	percentage.

     -p, --pool-name= (default:	ztest)
	   Pool	name.

     -f, --vdev-file-directory=	(default: /tmp)
	   File	directory for vdev files.

     -M, --multi-host
	   Multi-host; simulate	pool imported on remote	host.

     -E, --use-existing-pool
	   Use existing	pool (use existing pool	instead	of creating new	one).

     -T, --run-time= (default: 300s)
	   Total test run time.

     -P, --pass-time= (default:	60s)
	   Time	per pass.

     -F, --freeze-loops= (default: 50)
	   Max loops in	spa_freeze().

     -B, --alt-ztest=
	   Alternate ztest path.

     -C, --vdev-class-state=on|off|random (default: random)
	   The vdev allocation class state.

     -o, --option=variable=value
	   Set global variable to an unsigned 32-bit integer value (little-en-
	   dian	only).

     -G, --dump-debug
	   Dump	zfs_dbgmsg buffer before exiting due to	an error.

     -V, --verbose
	   Verbose (use	multiple times for ever	more verbosity).

EXAMPLES
     To	override /tmp as your location for block files,	you can	use the	-f op-
     tion:
	   # ztest -f /

     To	get an idea of what ztest is actually testing try this:
	   # ztest -f /	-VVV

     Maybe you'd like to run ztest for longer? To do so	simply use the -T op-
     tion and specify the runlength in seconds like so:
	   # ztest -f /	-V -T 120

ENVIRONMENT VARIABLES
     ZFS_HOSTID=id
	 Use id	instead	of the SPL hostid to identify this host.  Intended for
	 use with ztest, but this environment variable will affect any utility
	 which uses libzpool, including	zpool(8).  Since the kernel is unaware
	 of this setting, results with utilities other than ztest are unde-
	 fined.

     ZFS_STACK_SIZE=stacksize
	 Limit the default stack size to stacksize bytes for the purpose of
	 detecting and debugging kernel	stack overflows.  This value defaults
	 to 32K	which is double	the default 16K	Linux kernel stack size.

	 In practice, setting the stack	size slightly higher is	needed because
	 differences in	stack usage between kernel and user space can lead to
	 spurious stack	overflows (especially when debugging is	enabled).  The
	 specified value will be rounded up to a floor of PTHREAD_STACK_MIN
	 which is the minimum stack required for a NULL	procedure in user
	 space.

	 By default the	stack size is limited to 256K.

SEE ALSO
     zdb(1), zfs(1), zpool(1), spl(4)

FreeBSD	13.0			 May 26, 2021			  FreeBSD 13.0

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | EXAMPLES | ENVIRONMENT VARIABLES | SEE ALSO

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