Figure out how to properly use fstrim

[agrover]

Talk to Brian or Dennis on VDO team on how to use fstrim in an optimal fashion.

[leseb]

Is this still a topic? I didn't find fstrim being used anywhere in the codebase.
From my experience, it's discouraged to mount the fs with a discard option. Running scheduled fstrim jobs is preferred. The only use case where it is appropriate is if we have a fast device with fast discards and FTL/firmware that is known to behave reasonably well. Also, this might not be true as the device ages so periodic trims are encouraged.

Hope this helps.