Le 11/12/2018 à 15:32, Julien Rey a écrit :
Le 11/12/2018 14:13, quentin.bou...@cea.fr a écrit :
Le 11/12/2018 à 10:28, Julien Rey a écrit :
Le 10/12/2018 13:33, quentin.bou...@cea.fr a écrit :
Le 10/12/2018 à 12:00, Julien Rey a écrit :
Hello,
We are running lustre
2.8.0-RC5--PRISTINE-2.6.32-573.12.1.el6_lustre.x86_64.
Since thursday we are getting a "bad address" error when trying to
write on the lustre volume.
Looking at the logs on the MDS, we are getting this kind of
messages :
Dec 10 06:26:18 localhost kernel: Lustre:
9593:0:(llog_cat.c:93:llog_cat_new_log()) lustre-MDD0000: there
are no more free slots in catalog
Dec 10 06:26:18 localhost kernel: Lustre:
9593:0:(llog_cat.c:93:llog_cat_new_log()) Skipped 45157 previous
similar messages
Dec 10 06:26:18 localhost kernel: LustreError:
9593:0:(mdd_dir.c:887:mdd_changelog_ns_store()) lustre-MDD0000:
cannot store changelog record: type = 6, name =
'PEPFOLD-00016_bestene1-mc-SC-min-grompp.log', t =
[0x20000a58f:0x858e:0x0], p = [0x20000a57d:0x17fd9:0x0]: rc = -28
Dec 10 06:26:18 localhost kernel: LustreError:
9593:0:(mdd_dir.c:887:mdd_changelog_ns_store()) Skipped 45157
previous similar messages
I saw here that this issue was supposed to be solved in 2.8.0:
https://jira.whamcloud.com/browse/LU-6556
Could someone help us unlocking this situation ?
Thanks.
Hello,
The log messages don't point at a "bad address" issue but rather at
a "no space left on device" one ("rc = -28" --> -ENOSPC).
You most likely have, at some point, registered a changelog user on
your mds and that user is not consuming changelogs.
You can check this by running:
[mds0]# lctl get_param mdd.*.changelog_users
mdd.lustre-MDT0000.changelog_users=
current index: 3
ID index
cl1 0
The most important thing to look for is the distance between
"current index" and the index for "cl1", "cl2", ...
I expect for at least one changelog user, that distance is 2^32
(the maximum number of changelog records).
Note that changelog indexes wrap around (0, 1, 2, ..., 4294967295,
0, 1, ...).
If I am right, then you can either deregister the changelog user:
[mds0]# lctl --device lustre-MDT0000 changelog_deregister cl1
or acknowledge the records:
[client]# lfs changelog_clear lustre-MDT0000 cl1 0
(clearing with index 0 is a shortcut for "acknowledge every
changelog records")
Both those options may take a while.
There is a third one that might yield faster result, but it is also
much more dangerous to use (you might want to check with your
support first) :
[mds0]# umount /dev/mdt0
[mds0]# mount -t ldiskfs /dev/mdt0 /mnt/lustre-mdt0
[mds0]# rm /mnt/lustre-mdt0/changelog_catalog
[mds0]# rm /mnt/lustre-mdt0/changelog_users
[mds0]# umount /dev/mdt0
[mds0]# mount -t lustre /dev/mdt0 <...> # remount the mdt where it was
*I cannot garantee this will not trash your filesystem. Use at your
own risk.
*
---
In recent versions (2.12, maybe even 2.10), lustre comes with a
builtin garbage collector for slow/inactive changelog users.
Regards,
Quentin Bouget
Hello Quentin,
Many thanks for your quick reply.
This is what I got when I issued the command you suggested:
[root@lustre-mds]# lctl get_param mdd.*.changelog_users
mdd.lustre-MDT0000.changelog_users=
current index: 4160462682
ID index
cl1 21020582
I then issued the following command:
[root@lustre-mds]# lctl --device lustre-MDT0000 changelog_deregister cl1
It's been running for almost 20 hours now. Do you have an estimation
of the time it could take ?
When you deregister a changelog user: every changelog record has to
be invalidated (maybe this is batched, but I don't know enough about
the on-disk structure to say).
I do not recall ever waiting that long. Then again, I never
personally deregistered a changelog users with that many pending
changelog records.
The changelog_deregister command still hasn't finished yet. Is there
any way to track the state of the purge of records ?
I believe there is an "llog_reader" implemented in the lustre sources,
but I never really used it.
If you just want to make sure Lustre is doing something, you can have
a look at your mdt0: invalidating changelog records should generate a
high load of small random writes.
If the device is idle, something is probably wrong.
Hard to tell. iostat doesn't show much I/O.
Is your filesystem still unavailable?
The following command doesn't show any registered changelog user:
cat /proc/fs/lustre/mdd/lustre-MDT0000/changelog_users
I tried to mount the lustre volume on a client. I don't get the "Bad
Address" error anymore.
Best,
Yes, I don't think you need to wait for "changelog_deregister" to
complete to start using your filesystem again.
If there is not any changelog user registered on your system, changelog
records are not emitted.
Just try to wait until "changelog_deregister" completes before
registering a new changelog user. =)
Best,
--
Julien REY
Plate-forme RPBS
Molécules Thérapeutiques In Silico (MTi)
Université Paris Diderot - Paris VII
tel : 01 57 27 83 95
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Quentin
--
Julien REY
Plate-forme RPBS
Molécules Thérapeutiques In Silico (MTi)
Université Paris Diderot - Paris VII
tel : 01 57 27 83 95
_______________________________________________
lustre-discuss mailing list
lustre-discuss@lists.lustre.org
http://lists.lustre.org/listinfo.cgi/lustre-discuss-lustre.org
Cheers,
Quentin
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