Chapitre 5. Trim options on an LVM-VDO volume

You can mount your file system with the discard option, which informs the VDO volume of the unused space. Another option is to use the fstrim application, which is an on-demand discarding, or mount -o discard command for immediate discarding.

When using the fstrim application, the admin needs to schedule and monitor an additional process, while using mount -o discard command allows for immediate recovery of space when possible.

Note that it is currently recommended to use fstrim application to discard unused blocks rather than the discard mount option because the performance impact of this option can be quite severe. For this reason, nodiscard is the default.