un “xfs_quota -x” as root and set quota controls on an ordinary user.

# sudo /usr/sbin/xfs_quota -x /mnt/xfstest
xfs_quota> limit bsoft=10m bhard=20m youruser

Investigate how the limit command has affected your user.

# /usr/sbin/xfs_quota -c 'quota -v'

Exceed the soft quota. Note that while your (soft) quota has been exceeded you can still write files.

# cd /mnt/xfstest
# dd if=/dev/urandom of=./testfile1 bs=1k count=15000
# /usr/sbin/xfs_quota -c 'quota' /mnt/xfstest
# ls > testfile2

Exceeding hard Quota

# rm testfile1 testfile2
# dd if=/dev/urandom of=./testfile1 bs=1k count=30000
dd: writing `./testfile': Disk quota exceeded
20417+0 records in
20416+0 records out
20905984 bytes (21 MB) copied, 4.20713 seconds, 5.0 MB/s

Run the quota command and examine the output.

# /usr/sbin/xfs_quota -c quota
Disk quotas for User youruser (500)
Filesystem              Blocks      Quota      Limit  Warn/Time      Mounted on
/dev/hdb1                20416      10240      20480   00  [6 days] /mnt/xfstest

Run the generic repquota command to compare the behavior.

# /usr/sbin/repquota /mnt/xfstest
*** Report for user quotas on device /dev/hdb1
Block grace time: 7days; Inode grace time: 7days
                        Block limits                File limits
User            used    soft    hard  grace    used  soft  hard  grace
----------------------------------------------------------------------
youruser   +-   20416   10240   20480  6days       1     0     0

Remove the test files created above and investigate the affects of quotas on holey files. Holey files can be created with dd

# dd if=/dev/urandom of=./testfile bs=1k count=1 seek=2000000

Compare the outputs of

# ls -hl
# du -h *
# /usr/sbin/xfs_quota -c quota

Experiment with inode quotas.

xfs_quota> limit isoft=5 ihard=10 youruser

Create files to exceed your soft and hard limits. Note that the xfs_quota quota command takes a -i option to report on inodes.

Experiment with group quotas. You will need to remount the filesystem after adding the gquota option to the fstab. xfs_quota commands use -g to indicate they are working with groups.