On Fri, Feb 3, 2017 at 10:40 AM, Zdenek Kabelac <zkabelac(a)redhat.com> wrote:
Dne 3.2.2017 v 18:23 Chris Murphy napsal(a):
>
> 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.
>
Hi
Please read doc about this option first
"this feature" = the proposed change, not issue_discards=0
--
Chris Murphy