usage: /usr/share/zfs/zfs-tests/bin/xattrtest [-hvycdrRk] [-n <nth>] [-f <files>] [-x <xattrs>]
       [-s <bytes>] [-p <path>] [-t <script> ] [-o <phase>]
  --help        -h           This help
  --verbose     -v           Increase verbosity
  --verify      -y           Verify xattr contents
  --nth         -n <nth>     Print every nth file
  --files       -f <files>   Set xattrs on N files
  --xattrs      -x <xattrs>  Set N xattrs on each file
  --size        -s <bytes>   Set N bytes per xattr
  --path        -p <path>    Path to files
  --synccaches  -c           Sync caches between phases
  --dropcaches  -d           Drop caches between phases
  --script      -t <script>  Exec script between phases
  --seed        -e <seed>    Random seed value
  --random      -r           Randomly sized xattrs [16-size]
  --randomvalue -R           Random xattr values
  --keep        -k           Don't unlink files
  --only        -o <num>     Only run phase N
                             0=all, 1=create, 2=setxattr,
                             3=getxattr, 4=unlink