mirror_zfs/man/man1/ztest.1
Olaf Faaland 379ca9cf2b Multi-modifier protection (MMP)
Add multihost=on|off pool property to control MMP.  When enabled
a new thread writes uberblocks to the last slot in each label, at a
set frequency, to indicate to other hosts the pool is actively imported.
These uberblocks are the last synced uberblock with an updated
timestamp.  Property defaults to off.

During tryimport, find the "best" uberblock (newest txg and timestamp)
repeatedly, checking for change in the found uberblock.  Include the
results of the activity test in the config returned by tryimport.
These results are reported to user in "zpool import".

Allow the user to control the period between MMP writes, and the
duration of the activity test on import, via a new module parameter
zfs_multihost_interval.  The period is specified in milliseconds.  The
activity test duration is calculated from this value, and from the
mmp_delay in the "best" uberblock found initially.

Add a kstat interface to export statistics about Multiple Modifier
Protection (MMP) updates. Include the last synced txg number, the
timestamp, the delay since the last MMP update, the VDEV GUID, the VDEV
label that received the last MMP update, and the VDEV path.  Abbreviated
output below.

$ cat /proc/spl/kstat/zfs/mypool/multihost
31 0 0x01 10 880 105092382393521 105144180101111
txg   timestamp  mmp_delay   vdev_guid   vdev_label vdev_path
20468    261337  250274925   68396651780       3    /dev/sda
20468    261339  252023374   6267402363293     1    /dev/sdc
20468    261340  252000858   6698080955233     1    /dev/sdx
20468    261341  251980635   783892869810      2    /dev/sdy
20468    261342  253385953   8923255792467     3    /dev/sdd
20468    261344  253336622   042125143176      0    /dev/sdab
20468    261345  253310522   1200778101278     2    /dev/sde
20468    261346  253286429   0950576198362     2    /dev/sdt
20468    261347  253261545   96209817917       3    /dev/sds
20468    261349  253238188   8555725937673     3    /dev/sdb

Add a new tunable zfs_multihost_history to specify the number of MMP
updates to store history for. By default it is set to zero meaning that
no MMP statistics are stored.

When using ztest to generate activity, for automated tests of the MMP
function, some test functions interfere with the test.  For example, the
pool is exported to run zdb and then imported again.  Add a new ztest
function, "-M", to alter ztest behavior to prevent this.

Add new tests to verify the new functionality.  Tests provided by
Giuseppe Di Natale.

Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Reviewed-by: Ned Bass <bass6@llnl.gov>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Olaf Faaland <faaland1@llnl.gov>
Closes #745
Closes #6279
2017-07-13 13:54:00 -04:00

176 lines
5.3 KiB
Groff

'\" t
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.\" Copyright (c) 2009 Oracle and/or its affiliates. All rights reserved.
.\" Copyright (c) 2009 Michael Gebetsroither <michael.geb@gmx.at>. All rights
.\" reserved.
.\"
.TH ztest 1 "2009 NOV 01" "ZFS on Linux" "User Commands"
.SH NAME
\fBztest\fR \- was written by the ZFS Developers as a ZFS unit test.
.SH SYNOPSIS
.LP
.BI "ztest <options>"
.SH DESCRIPTION
.LP
This manual page documents briefly the \fBztest\fR command.
.LP
\fBztest\fR 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
\fBztest\fR. In addition, a separate test development team wrote and
executed more functional and stress tests.
.LP
By default \fBztest\fR runs for ten minutes and uses block files
(stored in /tmp) to create pools rather than using physical disks.
Block files afford \fBztest\fR 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.
.LP
By default is non-verbose. This is why entering the command above will
result in \fBztest\fR quietly executing for 5 minutes. The -V option
can be used to increase the verbosity of the tool. Adding multiple -V
option is allowed and the more you add the more chatty \fBztest\fR
becomes.
.LP
After the \fBztest\fR 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 \fBztest\fR run by using the -E
option.
.SH OPTIONS
.HP
.BI "\-?" ""
.IP
Print a help summary.
.HP
.BI "\-v" " vdevs" " (default: 5)
.IP
Number of vdevs.
.HP
.BI "\-s" " size_of_each_vdev" " (default: 64M)"
.IP
Size of each vdev.
.HP
.BI "\-a" " alignment_shift" " (default: 9) (use 0 for random)"
.IP
Used alignment in test.
.HP
.BI "\-m" " mirror_copies" " (default: 2)"
.IP
Number of mirror copies.
.HP
.BI "\-r" " raidz_disks" " (default: 4)"
.IP
Number of raidz disks.
.HP
.BI "\-R" " raidz_parity" " (default: 1)"
.IP
Raidz parity.
.HP
.BI "\-d" " datasets" " (default: 7)"
.IP
Number of datasets.
.HP
.BI "\-t" " threads" " (default: 23)"
.IP
Number of threads.
.HP
.BI "\-g" " gang_block_threshold" " (default: 32K)"
.IP
Gang block threshold.
.HP
.BI "\-i" " initialize_pool_i_times" " (default: 1)"
.IP
Number of pool initialisations.
.HP
.BI "\-k" " kill_percentage" " (default: 70%)"
.IP
Kill percentage.
.HP
.BI "\-p" " pool_name" " (default: ztest)"
.IP
Pool name.
.HP
.BI "\-V(erbose)"
.IP
Verbose (use multiple times for ever more blather).
.HP
.BI "\-E(xisting)"
.IP
Use existing pool (use existing pool instead of creating new one).
.HP
.BI "\-T" " time" " (default: 300 sec)"
.IP
Total test run time.
.HP
.BI "\-z" " zil_failure_rate" " (default: fail every 2^5 allocs)
.IP
Injected failure rate.
.SH "EXAMPLES"
.LP
To override /tmp as your location for block files, you can use the -f
option:
.IP
ztest -f /
.LP
To get an idea of what ztest is actually testing try this:
.IP
ztest -f / -VVV
.LP
Maybe you'd like to run ztest for longer? To do so simply use the -T
option and specify the runlength in seconds like so:
.IP
ztest -f / -V -T 120
.SH "ENVIRONMENT VARIABLES"
.TP
.B "ZFS_HOSTID=id"
Use \fBid\fR 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 \fBzpool(8)\fR. Since the kernel is unaware of this setting
results with utilites other than ztest are undefined.
.TP
.B "ZFS_STACK_SIZE=stacksize"
Limit the default stack size to \fBstacksize\fR bytes for the purpose of
detecting and debugging kernel stack overflows. This value defaults to
\fB32K\fR which is double the default \fB16K\fR 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.
.SH "SEE ALSO"
.BR "spl-module-parameters (5)" ","
.BR "zpool (1)" ","
.BR "zfs (1)" ","
.BR "zdb (1)" ","
.SH "AUTHOR"
This manual page was transvered to asciidoc by Michael Gebetsroither
<gebi@grml.org> from http://opensolaris.org/os/community/zfs/ztest/