Defragment an ext4 filesystem. More information: e4defrag - manned.org.
- Defragment the filesystem:
e4defrag {{/dev/sdXN}}
- See how fragmented a filesystem is:
e4defrag -c {{/dev/sdXN}}
- Print errors and the fragmentation count before and after each file:
e4defrag -v {{/dev/sdXN}}