How to get Linux partition UUID

Ext3 file system UUID

tune2fs -l /dev/sda11 | grep UUID

Here is an output:

Filesystem UUID: 0827dce3-d1c0-41b1-bc6f-0d4cfa0a1849

XFS file system UUID

xfs_admin -u /dev/sda13

Here is an output:

UUID = f128170a-1ee4-4b4f-abe7-0acf169bb8ae

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