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 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 [-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 (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, 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)