Hi Dan, unfortunately, the file/directory names were generated like one would do for temporary files. No clue about their location. I would need to find such a file while it exists. Of course, I could execute a find on the snapshot ...
Just kidding. The large omap count is going down already, the first 4 are probably purged from the snapshots. Thanks and best regards, ================= Frank Schilder AIT Risø Campus Bygning 109, rum S14 ________________________________________ From: Dan van der Ster <d...@vanderster.com> Sent: 31 August 2021 15:44:41 To: Frank Schilder Cc: Patrick Donnelly; ceph-users Subject: Re: [ceph-users] LARGE_OMAP_OBJECTS: any proper action possible? Hi, I don't know how to find a full path from a dir object. But perhaps you can make an educated guess based on what you see in: rados listomapkeys --pool=con-fs2-meta1 1000eec35f5.01000000 | head -n 100 Those should be the directory entries. (s/_head//) -- Dan On Tue, Aug 31, 2021 at 2:31 PM Frank Schilder <fr...@dtu.dk> wrote: > > Dear Dan and Patrick, > > the find didn't return anything. With this and the info below, am I right to > assume that these were temporary working directories that got caught in a > snapshot (we use rolling snapshots)? > > I would really appreciate any ideas on how to find out the original file > system path of these large directories. I would like to advise the user(s) > that we have a special high-performance file system for temporary data. > > I can't find indications of performance problems with the meta-data pool. > After the re-deployment of OSDs with quadrupling the OSD count, the meta data > pool seems to perform very well. The find did run over a 1.3PB file system in > under 18hours. > > However, running this find on the root got me caught in another problem: > https://lists.ceph.io/hyperkitty/list/ceph-users@ceph.io/thread/HKEBXXRMX5WA5Y6JFM34WFPMWTCMPFCG/#EMHNSHZIPFZZ5QYS6B4VW3LUGL6HDTOP > > Apparently, the meta data performance is now so high that a single client can > crash an MDS daemon and even take the MDS cluster with it. > > Best regards, > ================= > Frank Schilder > AIT Risø Campus > Bygning 109, rum S14 > > ________________________________________ > From: Frank Schilder > Sent: 30 August 2021 16:18:02 > To: ceph-users > Cc: Dan van der Ster; Patrick Donnelly > Subject: Re: [ceph-users] LARGE_OMAP_OBJECTS: any proper action possible? > > Dear Dan and Patrick, > > I have the suspicion that I'm looking at large directories in the snapshots > that do no longer exist any more on the file system. Hence, the omap objects > are not fragmented as explained in the tracker issue. Here is the info as you > asked me to pull out: > > > find /cephfs -type d -inum 1099738108263 > > The find didn't return yet. Would be great to find which user is doing that. > Unfortunately, I don't believe the directory still exists. > > > rados -p cephfs_metadata listomapkeys 1000d7fd167.02800000 > > I did this on a different object: > > # rados listomapkeys --pool=con-fs2-meta1 1000eec35f5.01000000 | wc -l > 216000 > > This matches with the log message. I guess these keys are file/dir names? > Then yes, its a huge directory. > > > Please try the resolutions suggested in: > > https://tracker.ceph.com/issues/45333 > > If I understand correctly, the INODE.00000000 objects contain the path > information: > > [root@gnosis ~]# rados listxattr --pool=con-fs2-meta1 1000eec35f5.01000000 > [root@gnosis ~]# rados listxattr --pool=con-fs2-meta1 1000eec35f5.00000000 > layout > parent > > Decoding the meta info in the parent attribute gives: > > [root@gnosis ~]# rados getxattr --pool=con-fs2-meta1 1000eec35f5.00000000 > parent | ceph-dencoder type inode_backtrace_t import - decode dump_json > { > "ino": 1099761989109, > "ancestors": [ > { > "dirino": 1552, > "dname": "1000eec35f5", > "version": 882614706 > }, > { > "dirino": 257, > "dname": "stray6", > "version": 563853824 > } > ], > "pool": 12, > "old_pools": [] > } > > This smells a lot like a deleted directory in a snapshot, moved to one of the > stray object bucket. The result is essentially the same for all large omap > objects except for the stray number. Is it possible to figure out the > original location in the file system path? > > I guess I have to increase the warning threshold or live with the warning > message, neither of which is preferred. It would be great if you could help > me find the original path so I can identify the user and advice him/her on > how to organise his/her files. > > Thanks and best regards, > ================= > Frank Schilder > AIT Risø Campus > Bygning 109, rum S14 > > ________________________________________ > From: Patrick Donnelly <pdonn...@redhat.com> > Sent: 27 August 2021 19:16:16 > To: Frank Schilder > Cc: ceph-users > Subject: Re: [ceph-users] LARGE_OMAP_OBJECTS: any proper action possible? > > Hi Frank, > > On Wed, Aug 25, 2021 at 6:27 AM Frank Schilder <fr...@dtu.dk> wrote: > > > > Hi all, > > > > I have the notorious "LARGE_OMAP_OBJECTS: 4 large omap objects" warning and > > am again wondering if there is any proper action one can take except "wait > > it out and deep-scrub (numerous ceph-users threads)" or "ignore > > (https://docs.ceph.com/en/latest/rados/operations/health-checks/#large-omap-objects)". > > Only for RGWs is a proper action described, but mine come from MDSes. Is > > there any way to ask an MDS to clean up or split the objects? > > > > The disks with the meta-data pool can easily deal with objects of this > > size. My question is more along the lines: If I can't do anything anyway, > > why the warning? If there is a warning, I would assume that one can do > > something proper to prevent large omap objects from being born by an MDS. > > What is it? > > Please try the resolutions suggested in: https://tracker.ceph.com/issues/45333 > > -- > Patrick Donnelly, Ph.D. > He / Him / His > Principal Software Engineer > Red Hat Sunnyvale, CA > GPG: 19F28A586F808C2402351B93C3301A3E258DD79D > _______________________________________________ ceph-users mailing list -- ceph-users@ceph.io To unsubscribe send an email to ceph-users-le...@ceph.io