Dear Xiubo, I uploaded the cache dump, the MDS log and the dmesg log containing the snaptrace dump to ceph-post-file: 763955a3-7d37-408a-bbe4-a95dc687cd3f Sorry, I forgot to add user and description this time. A question about trouble shooting. I'm pretty sure I know the path where the error is located. Would a "ceph tell mds.1 scrub start / recursive repair" be able to discover and fix broken snaptraces? If not I'm awaiting further instructions. Best regards, ================= Frank Schilder AIT Risø Campus Bygning 109, rum S14 ________________________________________ From: Xiubo Li <xiubli@xxxxxxxxxx> Sent: Friday, May 12, 2023 3:44 PM To: Frank Schilder; ceph-users@xxxxxxx Subject: Re: Re: mds dump inode crashes file system On 5/12/23 20:27, Frank Schilder wrote: > Dear Xiubo and others. > >>> I have never heard about that option until now. How do I check that and how to I disable it if necessary? >>> I'm in meetings pretty much all day and will try to send some more info later. >> $ mount|grep ceph > I get > > MON-IPs:SRC on DST type ceph (rw,relatime,name=con-fs2-rit-pfile,secret=<hidden>,noshare,acl,mds_namespace=con-fs2,_netdev) > > so async dirop seems disabled. Yeah. >> Yeah, the kclient just received a corrupted snaptrace from MDS. >> So the first thing is you need to fix the corrupted snaptrace issue in cephfs and then continue. > Ooookaaayyyy. I will take it as a compliment that you seem to assume I know how to do that. The documentation gives 0 hits. Could you please provide me with instructions of what to look for and/or what to do first? There is no doc about this as I know. >> If possible you can parse the above corrupted snap message to check what exactly corrupted. >> I haven't get a chance to do that. > Again, how would I do that? Is there some documentation and what should I expect? Currently there is no easy way to do this as I know, last time I have parsed the corrupted binary data to the corresponding message manully. And then we could know what exactly has happened for the snaptrace. >> You seems didn't enable the 'osd blocklist' cephx auth cap for mon: > I can't find anything about an osd blocklist client auth cap in the documentation. Is this something that came after octopus? Our caps are as shown in the documentation for a ceph fs client (https://docs.ceph.com/en/octopus/cephfs/client-auth/), the one for mon is "allow r": > > caps mds = "allow rw path=/shares" > caps mon = "allow r" > caps osd = "allow rw tag cephfs data=con-fs2" Yeah, it seems the 'osd blocklist' was disabled. As I remembered if enabled it should be something likes: caps mon = "allow r, allow command \"osd blocklist\"" > >> I checked that but by reading the code I couldn't get what had cause the MDS crash. >> There seems something wrong corrupt the metadata in cephfs. > He wrote something about an invalid xattrib (empty value). It would be really helpful to get a clue how to proceed. I managed to dump the MDS cache with the critical inode in cache. Would this help with debugging? I also managed to get debug logs with debug_mds=20 during a crash caused by an "mds dump inode" command. Would this contain something interesting? I can also pull the rados objects out and can upload all of these files. Yeah, possibly. Where is the logs ? > I managed to track the problem down to a specific folder with a few files (I'm not sure if this coincides with the snaptrace issue, we might have 2 issues here). I made a copy of the folder and checked that an "mds dump inode" for the copy does not crash the MDS. I then moved the folders for which this command causes a crash to a different location outside the mounts. Do you think this will help? I'm wondering if after taking our daily snapshot tomorrow we end up in the degraded situation again. > > I really need instructions for how to check what is broken without an MDS crash and then how to fix it. Firstly we need to know where the corrupted metadata is. I think the mds debug logs and the above corrupted snaptrace could help. Need to parse that corrupted binary data. Thanks _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx
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