Closed ymartin59 closed 10 years ago
It is not relevant to select cron periodicity per filesystem.
It should be evaluated for a whole SSD device on its own, as all
filesystems allocated on a single device share the same free block pool.
They may share the same block pool, but fstrim does only discard unused blocks on a mounted filesystem and not on the whole block pool.
[...]
fstrim is used on a mounted filesystem to discard (or "trim") blocks which are
not in use by the filesystem.
[...]
So as long as fstrim does not free up the space on the whole disk, it is relevant to trim it per filesystem.
You may have a small almost full filesystem with almost no write activities
like "/opt" but if the SSD is only allocated to 50% there is no need to trig
fstrim hourly.
I agree with you. But in such a case i would just recommend to NOT put /opt into SSD_MOUNT_POINTS. Therefore this filesystem will also not be trimmed.
Right. I wrote my message with the idea the script may process all filesystems in a whole by detecting where fstrim is required. I am testing some code...
It is not relevant to select cron periodicity per filesystem. It should be evaluated for a whole SSD device on its own, as all filesystems allocated on a single device share the same free block pool. You may have a small almost full filesystem with almost no write activities like "/opt" but if the SSD is only allocated to 50% there is no need to trig fstrim hourly. To evaluate SSD allocation, unallocated partition space and unallocated LVM volume group space must be taken into account too.