How to defragment XFS

There is an easy way to find out if your XFS partition needs defragmentation. Here is the command (it is part of package xfsprogs):

deby:~# xfs_db -c frag -r /dev/sda10
actual 2903, ideal 2418, fragmentation factor 16.71%

Once you see it is pretty high, e.g. above 40% you would need to issue the following command that defragment the drive:

deby:~# xfs_fsr -v /dev/sda10
/home start inode=0