Looked into this further and it looks like a kernel bug. If I downgraded the running kernel everything started working again. I've reported here https://bugs.centos.org/view.php?id=10191 with some more details. Thanks On 20 January 2016 at 11:36, Tim Robinson <terobinson at gmail.com> wrote: > I still get the "the discard operation is not supported" fstrim error > when the LVs are set to "nopassdown" > > Seems that when I use ext4 the fstrim reports that it worked but the > LVs Data% does not decrease after the fstrim. xfs just throws the > error. > > I've also been looking at the output of lsblk -D > > # lsblk -D > NAME DISC-ALN DISC-GRAN DISC-MAX DISC-ZERO > xvdb 0 0B 0B 0 > ├─data-pool00_tmeta 0 0B 0B 0 > │ └─data-pool00-tpool 0 0B 0B 0 > │ ├─data-pool00 0 0B 0B 0 > │ └─data-data 0 0B 0B 0 > └─data-pool00_tdata 0 0B 0B 0 > └─data-pool00-tpool 0 0B 0B 0 > ├─data-pool00 0 0B 0B 0 > └─data-data 0 0B 0B 0 > > I expect the DISC-GRAN and DISC-MAX to be greater than 0B. > > > On 20 January 2016 at 09:46, Chris Murphy <lists at colorremedies.com> wrote: >> My guess? The passthrough is causing the error when the command passes >> through to the actual device, which doesn't support Trim. >> >> I don't know how it actually works, but you can try to poke it with this >> stick: copy a large file to this LV. Check the LV with lvdisplay. Delete >> the file. Fstrim. Lvdisplay. Now compare the two lvdisplay results. >> >> It should show the PEs used are less after fstrim. >> >> >> Chris Murphy >> _______________________________________________ >> CentOS mailing list >> CentOS at centos.org >> https://lists.centos.org/mailman/listinfo/centos