Provided by: xfsprogs_6.1.0-1ubuntu1_amd64 bug


       xfs_info - display XFS filesystem geometry information


       xfs_info [ -t mtab ] [ mount-point | block-device | file-image ]
       xfs_info -V


       xfs_info  displays geometry information about an existing XFS filesystem.  The mount-point
       argument is the pathname of a directory where the filesystem is mounted.  The block-device
       or  file-image  contain a raw XFS filesystem.  The existing contents of the filesystem are


       -t     Specifies an alternate mount table file (default is /proc/mounts if it exists, else
              /etc/mtab).   This is used when working with filesystems mounted without writing to
              /etc/mtab file - refer to mount(8) for further details.  This option has no  effect
              with the block-device or file-image parameters.

       -V     Prints  the version number and exits. The mount-point argument is not required with


       Understanding xfs_info output.

       Suppose one has the following "xfs_info /dev/sda" output:

         meta-data=/dev/pmem0             isize=512    agcount=8, agsize=5974144 blks
                  =                       sectsz=512   attr=2, projid32bit=1
                  =                       crc=1        finobt=1, sparse=1, rmapbt=1
                  =                       reflink=1
         data     =                       bsize=4096   blocks=47793152, imaxpct=25
                  =                       sunit=32     swidth=128 blks
         naming   =version 2              bsize=4096   ascii-ci=0, ftype=1
         log      =internal log           bsize=4096   blocks=23336, version=2
                  =                       sectsz=512   sunit=0 blks, lazy-count=1
         realtime =none                   extsz=4096   blocks=0, rtextents=0

       Here, the data section of the output indicates "bsize=4096", meaning the data  block  size
       for  this  filesystem  is 4096 bytes.  This section also shows "sunit=32 swidth=128 blks",
       which means the stripe unit is 32*4096 bytes = 128  kibibytes  and  the  stripe  width  is
       128*4096  bytes = 512 kibibytes.  A single stripe of this filesystem therefore consists of
       four stripe units (128 blocks / 32 blocks per unit).


       mkfs.xfs(8), md(4), lvm(8), mount(8).