On Fri, Feb 3, 2017 at 10:18 AM, Chris Adams <linux(a)cmadams.net> wrote:
Once upon a time, Chris Murphy <lists(a)colorremedies.com> said:
> Further I wonder if /etc/lvm/lvm.conf needs
> issue_discards = 1
>
> Both / and /home are actually LV's which are made from the LUKS PV. So
> trim pass down from dmcrypt to block device isn't enough to do
> anything.
LVM passes discards through automatically, assuming the block device
under the PV supports them. The issue_discards option tells LVM to
issue discards itself when PV space is released (e.g. an LV is
removed/reduced).
Yep. I just tested it with the default issue_discards=0 and fstrim -v
does work on an LV.
Nevertheless I don't understand the benefit of this feature if
fstrim.service is not enabled by default; nor is a discard mount
option set for the file system in fstab.
--
Chris Murphy