Sorry some typo. It is mclock. Exact parameter osd_recovery_max_active_ssd/hdd. Is 10, to reduce you have to override mclock to true. Restarting osd daemon alone will solve your issue. Regards Dev On Fri, 2 May 2025 at 9:07 AM, Devender Singh <devender@netskrt.io> wrote:
Hello
Try restarting osds showing slow ops. Also if any recovery going on then max recovery drives for Malcom is 10 try reducing it. Will resolve this issue. If it persist for a drive then check for smart TK for errors and replace that drive.
Regards Dev
On Fri, 2 May 2025 at 8:45 AM, Maged Mokhtar <mmokhtar@petasan.org> wrote:
On 02/05/2025 13:57, Frédéric Nass wrote:
To clarify, there's no "issue" with the code itself. It's just that the code now reveals a potential "issue" with the OSD's underlying device, as Igor explained.
This warning can pop up starting from Quincy v17.2.8 (PR 59468), Reef v18.2.5 (PR #59466) and Squid v19.2.1 (PR #59464).
Regards, Frédéric.
Thanks Igor and Frederic for the clarifications.
However, this begs the question, what should users do see-ing such slow ops? From quoted link:
https://docs.ceph.com/en/latest/rados/operations/health-checks/#bluestore-sl... Which states it could be a drive issue, but not always...
So i think it could be helpful to share information/experiences of what users find to be the root cause of such issues. From our side:
1) With Octopus and earlier, we rarely saw such logs, and when they happened, it was mainly bad drives.
2) When we made an upgrade from Octopus->Quincy, we started to see more users complain. The complaint was not always due to a warning, but generally slower performance + higher latencies seen on charts + we can see it in the logs for a time period like: grep -r "slow operation observed for" /var/log/ceph | grep "2024-11"
3) Many users with issue, reported improvement when they stopped/reduced bulk deletions like heavy patterns of block rbd trim/discard/reclaim. This recommendation was influenced by messages from Igor and Mark Nelson on slow bulk deletions. It was also noticeable that after stopping trim, the cluster will not report issues even at significantly higher client load. This constituted the larger portion of issues we saw.
4) Generally performing an offline db compaction also helped: ceph-kvstore-tool bluestore-kv /var/lib/ceph/osd/ceph-XX compact
5) For non-db related warnings, some older OSDs had high fragmentation ceph daemon osd.XX bluestore allocator score block Deleting and re-adding the same drive helped slow ops.
6) To a lesser extent, the logs do indicate a defective drive or a drive with a different model/type that has much less performance than the other models in cluster/pool.
/Maged
----- Le 2 Mai 25, à 12:36, Eugen Block eblock@nde.ag a écrit :
The link Frederic shared is for 19.2.1, so yes, the new warning appeared in 19.2.1 as well.
Zitat von Laimis Juzeliūnas <laimis.juzeliunas@oxylabs.io>:
Hi all,
Could this also be an issue with 19.2.2? We have seen few of these warnings right after upgrading from 19.2.0. A simple OSD restart removed them, but we haven’t seen them before. There are some users on the Ceph Slack channels discussing this observation in 19.2.2 as well.
Best, Laimis J.
On 2 May 2025, at 13:11, Igor Fedotov <igor.fedotov@croit.io> wrote:
Hi Everyone,
well, indeed this warning has been introduced in 18.2.6.
But I wouldn't say that's not an issue. Having it permanently visible (particularly for a specific OSD only) might indicate some issues with this OSD which could negatively impact overall cluster performance.
OSD log to be checked for potential clues and more research on the root cause is recommended.
And once again - likely that's not a regression in 18.2.6 but rather some additional diagnostics brought by the release which reveals a potential issue.
Thanks,
Igor
On 02.05.2025 11:19, Frédéric Nass wrote: > Hi Michel, > > This is not an issue. It's a new warning that can be adjusted or > muted. Check this thread [1] and this part [2] of the Reef > documentation about this new alert. > Came to Reef with PR #59466 [3]. > > Cheers, > Frédéric. > > [1] >
> [2] > https://www.google.com/url?q=https://docs.ceph.com/en/latest/rados/operations/health-checks/%23bluestore-slow-op-alert&source=gmail-imap&ust=1746785596000000&usg=AOvVaw21VoozoT2KT6FESbkkVJ_w > [3] > https://www.google.com/url?q=https://github.com/ceph/ceph/pull/59466&source=gmail-imap&ust=1746785596000000&usg=AOvVaw0nnpOvrWFLB1lAk0Ekms1i > > ----- Le 2 Mai 25, à 9:44, Michel Jouvin > michel.jouvin@ijclab.in2p3.fr a écrit : > >> Hi, >> >> Since our upgrade to 18.2.6 2 days ago, our cluster is reporting
>> warning "1 OSD(s) experiencing slow operations in BlueStore": >> >> [root@dig-osd4 bluestore-slow-ops]# ceph health detail >> HEALTH_WARN 1 OSD(s) experiencing slow operations in BlueStore >> [WRN] BLUESTORE_SLOW_OP_ALERT: 1 OSD(s) experiencing slow operations in >> BlueStore >> osd.247 observed slow operation indications in BlueStore >> >> I have never seen this warning before so I've the feeling it is somehow >> related to the upgrade and it doesn't seem related to the regression >> mentioned in another thread (that should result in an OSD crash). >> Googling quickly, I found this reported on 19.2.1 with SSD where in my >> case it is an HDD. I don't know if the workaround mentioned in the issue >> (bdev_xxx_discard=true) also applies to 18.2.6... >> >> Did somebody saw this in 18.2.x? Any recommandation? Our plan was, >> according to best practicies described recently in another thread to >> move from 18.2.2 to 18.2.6 and then from 18.2.6 to 19.2.2... Will 19.2.2 >> clear this issue (at the risk of others as it is probably not >> widely used)? >> >> Best regards, >> >> Michel >> _______________________________________________ >> ceph-users mailing list -- ceph-users@ceph.io >> To unsubscribe send an email to ceph-users-leave@ceph.io > _______________________________________________ > ceph-users mailing list -- ceph-users@ceph.io > To unsubscribe send an email to ceph-users-leave@ceph.io _______________________________________________ ceph-users mailing list -- ceph-users@ceph.io To unsubscribe send an email to ceph-users-leave@ceph.io
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