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 pool 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 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 [-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 Force an error into the contents of a file.

    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 (ex. 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, or
    nxio
        for an ENXIO error where reopening the device will fail.

    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, which 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 failure
    Set the failure type to one of all, claim, free, read, or write.

-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)