zinject(8)

NAME

zinject – ZFS Fault Injector

DESCRIPTION

zinject creates artificial problems in a ZFS pool by simulating data corruption or device failures. This program is dangerous.

SYNOPSIS

zinject List injection records.

zinject -b objset:object:level:start:end [-f frequency] -amu [pool] Force an error into the pool at a bookmark.

zinject -c id|all Cancel injection records.

zinject -d vdev -A degrade|fault pool Force a vdev into the DEGRADED or FAULTED state.

zinject -d vdev -D latency:lanes [-T read|write] pool Add an artificial delay to I/O 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 I/O 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 I/O 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 are roughly equivalent to a single invocation of -D 10:2. This also means, that 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.

zinject -d vdev [-e device_error] [-L label_error] [-T failure] [-f frequency] [-F] pool Force a vdev error.

zinject -i seconds pool Add an artificial delay during the future import of a pool. This injector is automatically cleared after the import is finished.

zinject -E delay [-a] [-m] [-f freq] [-l level] [-r range] [-T iotype] [-t type|-b bookmark] Inject pipeline ready stage delays for the given object or bookmark. The delay is specified in milliseconds.

zinject -I [-s seconds|-g txgs] pool Simulate a hardware failure that fails to honor a cache flush.

zinject -p function pool Panic inside the specified function.

zinject -t data -C dvas [-e device_error] [-f frequency] [-l level] [-r range] [-amq] path|zvol Force an error into the contents of a file or zvol. For zvols, pass the path to the zvol block device.

zinject -t dnode -C dvas [-e device_error] [-f frequency] [-l level] [-amq] path Force an error into the metadnode for a file or directory.

zinject -t mos_type -C dvas [-e device_error] [-f frequency] [-l level] [-r range] [-amqu] pool Force an error into the MOS of a pool.

OPTIONS

-a

Flush the ARC before injection.

-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.

-C dvas

Inject the given error only into specific DVAs. The mask should be specified as a list of 0-indexed DVAs separated by commas (e.g. 0,2). This option is not applicable to logical data errors such as decompress and decrypt.

-d vdev

A vdev specified by path or GUID.

-e device_error

Specify

checksum

for an ECKSUM error,

decompress

for a data decompression error,

decrypt

for a data decryption error,

corrupt

to flip a bit in the data after a read,

dtl

for an ECHILD error,

io

for an EIO error where reopening the device will succeed,

nxio

for an ENXIO error where reopening the device will fail, or

io-prefail

to drop the IO without executing it and return failure, or

noop

to drop the IO without executing it and return success.

For EIO and ENXIO, the "failed" reads or writes still occur. The probe simply sets the error value reported by the I/O pipeline so it appears the read or write failed. Decryption errors only currently work with file data.

-f frequency

Only inject errors a fraction of the time. Expressed as a real number percentage between 0.0001 and 100.

-F

Fail faster. Do fewer checks.

-f txgs

Run for this many transaction groups before reporting failure.

-h

Print the usage message.

-l level

Inject an error at a particular block level. The default is 0.

-L label_error

Set the label error region to one of nvlist, pad1, pad2, or uber.

-m

Automatically remount the underlying filesystem.

-q

Quiet mode. Only print the handler number added.

-r range

Inject an error over a particular logical range of an object, specified as start[,end]. Numeric suffixes (K, M, G, T, P, E) are accepted. The range will be translated to the appropriate blkid range according to the object's properties.

-s seconds

Run for this many seconds before reporting failure.

-T type

Inject the error into I/O of this type.

read, write, flush, claim, free

Fundamental I/O types

all

All fundamental I/O types

probe

Device probe I/O

-t mos_type

Set this to

mos

for any data in the MOS,

mosdir

for an object directory,

config

for the pool configuration,

bpobj

for the block pointer list,

spacemap

for the space map,

metaslab

for the metaslab, or

errlog

for the persistent error log.

-u

Unload the pool after injection.

ENVIRONMENT VARIABLES

ZFS_HOSTID

Run zinject in debug mode.

SEE ALSO

zfs(8), zpool(8)