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 undisturbed.
- -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 -V.
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).