zfs/man/man8/zinject.8

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.\" Copyright 2013 Darik Horn <dajhorn@vanadac.com>. All rights reserved.
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.TH zinject 8 "2013 FEB 28" "ZFS on Linux" "System Administration Commands"

.SH NAME
zinject \- ZFS Fault Injector
.SH DESCRIPTION
.BR zinject
creates artificial problems in a ZFS pool by simulating data corruption or device failures. This program is dangerous.
.SH SYNOPSIS
.TP
.B "zinject"
List injection records.
.TP
.B "zinject \-b \fIobjset:object:level:blkd\fB [\-f \fIfrequency\fB] [\-amu] \fIpool\fB"
Force an error into the pool at a bookmark.
.TP
.B "zinject \-c <\fIid\fB | all>
Cancel injection records.
.TP
.B "zinject \-d \fIvdev\fB \-A <degrade|fault> \fIpool\fB
Force a vdev into the DEGRADED or FAULTED state.
.TP
.B "zinject -d \fIvdev\fB -D latency:lanes \fIpool\fB

Add an artificial delay to IO requests on a particular
device, such that the requests take a minimum of 'latency'
milliseconds to complete. Each delay has an associated
number of 'lanes' which defines the number of concurrent
IO requests that can be processed.

For example, with a single lane delay of 10 ms (-D 10:1),
the device will only be able to service a single IO request
at a time with each request taking 10 ms to complete. So,
if only a single request is submitted every 10 ms, the
average latency will be 10 ms; but if more than one request
is submitted every 10 ms, the average latency will be more
than 10 ms.

Similarly, if a delay of 10 ms is specified to have two
lanes (-D 10:2), then the device will be able to service
two requests at a time, each with a minimum latency of
10 ms. So, if two requests are submitted every 10 ms, then
the average latency will be 10 ms; but if more than two
requests are submitted every 10 ms, the average latency
will be more than 10 ms.

Also note, these delays are additive. So two invocations
of '-D 10:1', is roughly equivalent to a single invocation
of '-D 10:2'. This also means, one can specify multiple
lanes with differing target latencies. For example, an
invocation of '-D 10:1' followed by '-D 25:2' will
create 3 lanes on the device; one lane with a latency
of 10 ms and two lanes with a 25 ms latency.

.TP
.B "zinject \-d \fIvdev\fB [\-e \fIdevice_error\fB] [\-L \fIlabel_error\fB] [\-T \fIfailure\fB] [\-f \fIfrequency\fB] [\-F] \fIpool\fB"
Force a vdev error.
.TP
.B "zinject \-I [\-s \fIseconds\fB | \-g \fItxgs\fB] \fIpool\fB"
Simulate a hardware failure that fails to honor a cache flush.
.TP
.B "zinject \-p \fIfunction\fB \fIpool\fB
Panic inside the specified function.
.TP
.B "zinject \-t data [\-e \fIdevice_error\fB] [\-f \fIfrequency\fB] [\-l \fIlevel\fB] [\-r \fIrange\fB] [\-amq] \fIpath\fB"
Force an error into the contents of a file.
.TP
.B "zinject \-t dnode [\-e \fIdevice_error\fB] [\-f \fIfrequency\fB] [\-l \fIlevel\fB] [\-amq] \fIpath\fB"
Force an error into the metadnode for a file or directory.
.TP
.B "zinject \-t \fImos_type\fB [\-e \fIdevice_error\fB] [\-f \fIfrequency\fB] [\-l \fIlevel\fB] [\-r \fIrange\fB] [\-amqu] \fIpool\fB"
Force an error into the MOS of a pool.
.SH OPTIONS
.TP
.BI "\-a"
Flush the ARC before injection.
.TP
.BI "\-b" " objset:object:level:start:end"
Force an error into the pool at this bookmark tuple. Each number is
in hexadecimal, and only one block can be specified.
.TP
.BI "\-d" " vdev"
A vdev specified by path or GUID.
.TP
.BI "\-e" " device_error"
Specify
.BR "checksum" " for an ECKSUM error,"
.BR "corrupt" " to flip a bit in the data after a read,"
.BR "dtl" " for an ECHILD error,"
.BR "io" " for an EIO error where reopening the device will succeed, or"
.BR "nxio" " for an ENXIO error where reopening the device will fail."
.TP
.BI "\-f" " frequency"
Only inject errors a fraction of the time. Expressed as a real number
percentage between 0.0001 and 100.
.TP
.BI "\-F"
Fail faster. Do fewer checks.
.TP
.BI "\-g" " txgs"
Run for this many transaction groups before reporting failure.
.TP
.BI "\-h"
Print the usage message.
.TP
.BI "\-l" " level"
Inject an error at a particular block level. The default is 0.
.TP
.BI "\-L" " label_error"
Set the label error region to one of
.BR " nvlist" ","
.BR " pad1" ","
.BR " pad2" ", or"
.BR " uber" "."
.TP
.BI "\-m"
Automatically remount the underlying filesystem.
.TP
.BI "\-q"
Quiet mode. Only print the handler number added.
.TP
.BI "\-r" " range"
Inject an error over a particular logical range of an object, which
will be translated to the appropriate blkid range according to the
object's properties.
.TP
.BI "\-s" " seconds"
Run for this many seconds before reporting failure.
.TP
.BI "\-T" " failure"
Set the failure type to one of
.BR " all" ","
.BR " claim" ","
.BR " free" ","
.BR " read" ", or"
.BR " write" "."
.TP
.BI "\-t" " mos_type"
Set this to
.BR "mos " "for any data in the MOS,"
.BR "mosdir " "for an object directory,"
.BR "config " "for the pool configuration,"
.BR "bpobj " "for the block pointer list,"
.BR "spacemap " "for the space map,"
.BR "metaslab " "for the metaslab, or"
.BR "errlog " "for the persistent error log."
.TP
.BI "\-u"
Unload the pool after injection.

.SH "ENVIRONMENT VARIABLES"
.TP
.B "ZINJECT_DEBUG"
Run \fBzinject\fR in debug mode.

.SH "AUTHORS"
This man page was written by Darik Horn <dajhorn@vanadac.com>
excerpting the \fBzinject\fR usage message and source code.

.SH "SEE ALSO"
.BR zpool (8),
.BR zfs (8)