Re: cannot use btrfs for nfs server

Ulli Horlacher
2021-07-10T06:56:19Z

On Fri 2021-07-09 (10:35), Chris Murphy wrote:

> But I don't really understand your workflow, or what the fstab or
> subvolume setup looks like. Are you able to share the cron job script,
> the fstab, and the full subvolume listing? btrfs subvolume list -ta
> /nfs/localhost/fex ?

/nfs/localhost/fex is just a test setup on a test server.
The production server does not use nfs so far, but we plan to migrate from
local disks to nfs. But before we do it, btrfs via nfs MUST work without
problems and error messages.

/nfs/localhost/fex is not in /etc/fstab, I have mounted it manually, as I
wrote in my previous mails. It is just a test.

root@tsmsrvj:# grep local /etc/exports
/data/fex localhost(rw,async,no_subtree_check,no_root_squash,fsid=20000001)

root@tsmsrvj:# mount -v localhost:/data/fex /nfs/localhost/fex
mount.nfs: timeout set for Sat Jul 10 08:47:57 2021
mount.nfs: trying text-based options 'vers=4.2,addr=127.0.0.1,clientaddr=127.0.0.1'

root@tsmsrvj:# snaprotate -v test 5 /data/fex/spool
$ btrfs subvolume snapshot -r /data/fex/spool /data/fex/spool/.snapshot/2021-07-10_0849.test
Create a readonly snapshot of '/data/fex/spool' in '/data/fex/spool/.snapshot/2021-07-10_0849.test'

root@tsmsrvj:# snaprotate -l
/data/fex/spool/.snapshot/2021-03-07_1453.test
/data/fex/spool/.snapshot/2021-03-07_1531.test
/data/fex/spool/.snapshot/2021-03-07_1532.test
/data/fex/spool/.snapshot/2021-03-07_1718.test
/data/fex/spool/.snapshot/2021-07-10_0849.test

root@tsmsrvj:# btrfs subvolume list /data
ID 257 gen 1466 top level 5 path fex
ID 270 gen 1471 top level 257 path fex/spool
ID 271 gen 21 top level 270 path fex/spool/.snapshot/2021-03-07_1453.test
ID 272 gen 23 top level 270 path fex/spool/.snapshot/2021-03-07_1531.test
ID 273 gen 25 top level 270 path fex/spool/.snapshot/2021-03-07_1532.test
ID 274 gen 27 top level 270 path fex/spool/.snapshot/2021-03-07_1718.test
ID 394 gen 1470 top level 270 path fex/spool/.snapshot/2021-07-10_0849.test

We cannot move the snapshots to a different directory. Our workflow
depends on snaprotate:

http://fex.belwue.de/linuxtools/snaprotate.html

--
Ullrich Horlacher Server und Virtualisierung
Rechenzentrum TIK
Universitaet Stuttgart E-Mail: horlacher@tik.uni-stuttgart.de
Allmandring 30a Tel: ++49-711-68565868
70569 Stuttgart (Germany) WWW: http://www.tik.uni-stuttgart.de/
REF:<CAJCQCtQvak-28B7eUf5zRnAeGK27qZaF-1ZZt=OAHk+2KmfsWQ@mail.gmail.com>