On Fri, Jun 11, 2021 at 05:55:02AM -0700, David Christensen wrote: > On 6/10/21 11:49 PM, Reco wrote: > > On Thu, Jun 10, 2021 at 11:43:12PM -0700, David Christensen wrote: > > > I don't bother with the 'discard' option in /etc/fstab, but perhaps I > > > should. The fstab(5) and mount(8) manual pages are unclear if > > > 'discard' applies to swap or ext4. > > > > swapon(8): > > > > -d, --discard[=policy] > > Enable swap discards ... The /etc/fstab mount options discard, > > discard=once, or discard=pages may also be used to enable discard flags. > > > > > > Therefore 'discard' can be applied to both ext4 and swap. > > Thank you for the clarification regarding trim and swap. > > Where do you see the information for ext4?
You just have to know where to look - ext4(5): discard/nodiscard Controls whether ext4 should issue discard/TRIM commands to the underlying block device when blocks are freed. This is useful for SSD devices and sparse/thinly-provisioned LUNs, but it is off by default until sufficient testing has been done. How exactly this ended in manpages section 5 (which is "File formats and conventions eg /etc/passwd") is anyone's guess. Reco