Discard operations only tell the drive that a LBA is eligible for GC. It&#x27;s basically a delete operation that explicitly can be deferred. It does not give the OS any input into when or how GC is done, and it doesn&#x27;t give the OS any way to observe any details about the GC process.<p>I think the recommendations for periodic fstrim of free space is due to filesystems usually not taking the time to issue a large number of discard operations when you delete a bunch of data. Even though discards should be faster than a synchronous erase command, not issuing any command to the drive is faster still.