Image? One? We start deleting images only to fix thsi (export/import)m before - 1-4 times per day (when VM destroyed)...
2015-08-21 1:44 GMT+03:00 Samuel Just <sj...@redhat.com>: > Interesting. How often do you delete an image? I'm wondering if > whatever this is happened when you deleted these two images. > -Sam > > On Thu, Aug 20, 2015 at 3:42 PM, Voloshanenko Igor > <igor.voloshane...@gmail.com> wrote: > > Sam, i try to understand which rbd contain this chunks.. but no luck. No > rbd > > images block names started with this... > > > >> Actually, now that I think about it, you probably didn't remove the > >> images for 3fac9490/rbd_data.eb5f22eb141f2.00000000000004ba/snapdir//2 > >> and 22ca30c4/rbd_data.e846e25a70bf7.0000000000000307/snapdir//2 > > > > > > > > > > 2015-08-21 1:36 GMT+03:00 Samuel Just <sj...@redhat.com>: > >> > >> Actually, now that I think about it, you probably didn't remove the > >> images for 3fac9490/rbd_data.eb5f22eb141f2.00000000000004ba/snapdir//2 > >> and 22ca30c4/rbd_data.e846e25a70bf7.0000000000000307/snapdir//2, but > >> other images (that's why the scrub errors went down briefly, those > >> objects -- which were fine -- went away). You might want to export > >> and reimport those two images into new images, but leave the old ones > >> alone until you can clean up the on disk state (image and snapshots) > >> and clear the scrub errors. You probably don't want to read the > >> snapshots for those images either. Everything else is, I think, > >> harmless. > >> > >> The ceph-objectstore-tool feature would probably not be too hard, > >> actually. Each head/snapdir image has two attrs (possibly stored in > >> leveldb -- that's why you want to modify the ceph-objectstore-tool and > >> use its interfaces rather than mucking about with the files directly) > >> '_' and 'snapset' which contain encoded representations of > >> object_info_t and SnapSet (both can be found in src/osd/osd_types.h). > >> SnapSet has a set of clones and related metadata -- you want to read > >> the SnapSet attr off disk and commit a transaction writing out a new > >> version with that clone removed. I'd start by cloning the repo, > >> starting a vstart cluster locally, and reproducing the issue. Next, > >> get familiar with using ceph-objectstore-tool on the osds in that > >> vstart cluster. A good first change would be creating a > >> ceph-objectstore-tool op that lets you dump json for the object_info_t > >> and SnapSet (both types have format() methods which make that easy) on > >> an object to stdout so you can confirm what's actually there. oftc > >> #ceph-devel or the ceph-devel mailing list would be the right place to > >> ask questions. > >> > >> Otherwise, it'll probably get done in the next few weeks. > >> -Sam > >> > >> On Thu, Aug 20, 2015 at 3:10 PM, Voloshanenko Igor > >> <igor.voloshane...@gmail.com> wrote: > >> > thank you Sam! > >> > I also noticed this linked errors during scrub... > >> > > >> > Now all lools like reasonable! > >> > > >> > So we will wait for bug to be closed. > >> > > >> > do you need any help on it? > >> > > >> > I mean i can help with coding/testing/etc... > >> > > >> > 2015-08-21 0:52 GMT+03:00 Samuel Just <sj...@redhat.com>: > >> >> > >> >> Ah, this is kind of silly. I think you don't have 37 errors, but 2 > >> >> errors. pg 2.490 object > >> >> 3fac9490/rbd_data.eb5f22eb141f2.00000000000004ba/snapdir//2 is > missing > >> >> snap 141. If you look at the objects after that in the log: > >> >> > >> >> 2015-08-20 20:15:44.865670 osd.19 10.12.2.6:6838/1861727 298 : > cluster > >> >> [ERR] repair 2.490 > >> >> 68c89490/rbd_data.16796a3d1b58ba.0000000000000047/head//2 expected > >> >> clone 2d7b9490/rbd_data.18f92c3d1b58ba.0000000000006167/141//2 > >> >> 2015-08-20 20:15:44.865817 osd.19 10.12.2.6:6838/1861727 299 : > cluster > >> >> [ERR] repair 2.490 > >> >> ded49490/rbd_data.11a25c7934d3d4.0000000000008a8a/head//2 expected > >> >> clone 68c89490/rbd_data.16796a3d1b58ba.0000000000000047/141//2 > >> >> > >> >> The clone from the second line matches the head object from the > >> >> previous line, and they have the same clone id. I *think* that the > >> >> first error is real, and the subsequent ones are just scrub being > >> >> dumb. Same deal with pg 2.c4. I just opened > >> >> http://tracker.ceph.com/issues/12738. > >> >> > >> >> The original problem is that > >> >> 3fac9490/rbd_data.eb5f22eb141f2.00000000000004ba/snapdir//2 and > >> >> 22ca30c4/rbd_data.e846e25a70bf7.0000000000000307/snapdir//2 are both > >> >> missing a clone. Not sure how that happened, my money is on a > >> >> cache/tiering evict racing with a snap trim. If you have any logging > >> >> or relevant information from when that happened, you should open a > >> >> bug. The 'snapdir' in the two object names indicates that the head > >> >> object has actually been deleted (which makes sense if you moved the > >> >> image to a new image and deleted the old one) and is only being kept > >> >> around since there are live snapshots. I suggest you leave the > >> >> snapshots for those images alone for the time being -- removing them > >> >> might cause the osd to crash trying to clean up the wierd on disk > >> >> state. Other than the leaked space from those two image snapshots > and > >> >> the annoying spurious scrub errors, I think no actual corruption is > >> >> going on though. I created a tracker ticket for a feature that would > >> >> let ceph-objectstore-tool remove the spurious clone from the > >> >> head/snapdir metadata. > >> >> > >> >> Am I right that you haven't actually seen any osd crashes or user > >> >> visible corruption (except possibly on snapshots of those two > images)? > >> >> -Sam > >> >> > >> >> On Thu, Aug 20, 2015 at 10:07 AM, Voloshanenko Igor > >> >> <igor.voloshane...@gmail.com> wrote: > >> >> > Inktank: > >> >> > > >> >> > > >> >> > > https://download.inktank.com/docs/ICE%201.2%20-%20Cache%20and%20Erasure%20Coding%20FAQ.pdf > >> >> > > >> >> > Mail-list: > >> >> > > https://www.mail-archive.com/ceph-users@lists.ceph.com/msg18338.html > >> >> > > >> >> > 2015-08-20 20:06 GMT+03:00 Samuel Just <sj...@redhat.com>: > >> >> >> > >> >> >> Which docs? > >> >> >> -Sam > >> >> >> > >> >> >> On Thu, Aug 20, 2015 at 9:57 AM, Voloshanenko Igor > >> >> >> <igor.voloshane...@gmail.com> wrote: > >> >> >> > Not yet. I will create. > >> >> >> > But according to mail lists and Inktank docs - it's expected > >> >> >> > behaviour > >> >> >> > when > >> >> >> > cache enable > >> >> >> > > >> >> >> > 2015-08-20 19:56 GMT+03:00 Samuel Just <sj...@redhat.com>: > >> >> >> >> > >> >> >> >> Is there a bug for this in the tracker? > >> >> >> >> -Sam > >> >> >> >> > >> >> >> >> On Thu, Aug 20, 2015 at 9:54 AM, Voloshanenko Igor > >> >> >> >> <igor.voloshane...@gmail.com> wrote: > >> >> >> >> > Issue, that in forward mode, fstrim doesn't work proper, and > >> >> >> >> > when > >> >> >> >> > we > >> >> >> >> > take > >> >> >> >> > snapshot - data not proper update in cache layer, and client > >> >> >> >> > (ceph) > >> >> >> >> > see > >> >> >> >> > damaged snap.. As headers requested from cache layer. > >> >> >> >> > > >> >> >> >> > 2015-08-20 19:53 GMT+03:00 Samuel Just <sj...@redhat.com>: > >> >> >> >> >> > >> >> >> >> >> What was the issue? > >> >> >> >> >> -Sam > >> >> >> >> >> > >> >> >> >> >> On Thu, Aug 20, 2015 at 9:41 AM, Voloshanenko Igor > >> >> >> >> >> <igor.voloshane...@gmail.com> wrote: > >> >> >> >> >> > Samuel, we turned off cache layer few hours ago... > >> >> >> >> >> > I will post ceph.log in few minutes > >> >> >> >> >> > > >> >> >> >> >> > For snap - we found issue, was connected with cache tier.. > >> >> >> >> >> > > >> >> >> >> >> > 2015-08-20 19:23 GMT+03:00 Samuel Just <sj...@redhat.com > >: > >> >> >> >> >> >> > >> >> >> >> >> >> Ok, you appear to be using a replicated cache tier in > front > >> >> >> >> >> >> of > >> >> >> >> >> >> a > >> >> >> >> >> >> replicated base tier. Please scrub both inconsistent pgs > >> >> >> >> >> >> and > >> >> >> >> >> >> post > >> >> >> >> >> >> the > >> >> >> >> >> >> ceph.log from before when you started the scrub until > >> >> >> >> >> >> after. > >> >> >> >> >> >> Also, > >> >> >> >> >> >> what command are you using to take snapshots? > >> >> >> >> >> >> -Sam > >> >> >> >> >> >> > >> >> >> >> >> >> On Thu, Aug 20, 2015 at 3:59 AM, Voloshanenko Igor > >> >> >> >> >> >> <igor.voloshane...@gmail.com> wrote: > >> >> >> >> >> >> > Hi Samuel, we try to fix it in trick way. > >> >> >> >> >> >> > > >> >> >> >> >> >> > we check all rbd_data chunks from logs (OSD) which are > >> >> >> >> >> >> > affected, > >> >> >> >> >> >> > then > >> >> >> >> >> >> > query > >> >> >> >> >> >> > rbd info to compare which rbd consist bad rbd_data, > after > >> >> >> >> >> >> > that > >> >> >> >> >> >> > we > >> >> >> >> >> >> > mount > >> >> >> >> >> >> > this > >> >> >> >> >> >> > rbd as rbd0, create empty rbd, and DD all info from bad > >> >> >> >> >> >> > volume > >> >> >> >> >> >> > to > >> >> >> >> >> >> > new > >> >> >> >> >> >> > one. > >> >> >> >> >> >> > > >> >> >> >> >> >> > But after that - scrub errors growing... Was 15 > errors.. > >> >> >> >> >> >> > .Now > >> >> >> >> >> >> > 35... > >> >> >> >> >> >> > We > >> >> >> >> >> >> > laos > >> >> >> >> >> >> > try to out OSD which was lead, but after rebalancing > this > >> >> >> >> >> >> > 2 > >> >> >> >> >> >> > pgs > >> >> >> >> >> >> > still > >> >> >> >> >> >> > have > >> >> >> >> >> >> > 35 scrub errors... > >> >> >> >> >> >> > > >> >> >> >> >> >> > ceph osd getmap -o <outfile> - attached > >> >> >> >> >> >> > > >> >> >> >> >> >> > > >> >> >> >> >> >> > 2015-08-18 18:48 GMT+03:00 Samuel Just > >> >> >> >> >> >> > <sj...@redhat.com>: > >> >> >> >> >> >> >> > >> >> >> >> >> >> >> Is the number of inconsistent objects growing? Can > you > >> >> >> >> >> >> >> attach > >> >> >> >> >> >> >> the > >> >> >> >> >> >> >> whole ceph.log from the 6 hours before and after the > >> >> >> >> >> >> >> snippet > >> >> >> >> >> >> >> you > >> >> >> >> >> >> >> linked above? Are you using cache/tiering? Can you > >> >> >> >> >> >> >> attach > >> >> >> >> >> >> >> the > >> >> >> >> >> >> >> osdmap > >> >> >> >> >> >> >> (ceph osd getmap -o <outfile>)? > >> >> >> >> >> >> >> -Sam > >> >> >> >> >> >> >> > >> >> >> >> >> >> >> On Tue, Aug 18, 2015 at 4:15 AM, Voloshanenko Igor > >> >> >> >> >> >> >> <igor.voloshane...@gmail.com> wrote: > >> >> >> >> >> >> >> > ceph - 0.94.2 > >> >> >> >> >> >> >> > Its happen during rebalancing > >> >> >> >> >> >> >> > > >> >> >> >> >> >> >> > I thought too, that some OSD miss copy, but looks > like > >> >> >> >> >> >> >> > all > >> >> >> >> >> >> >> > miss... > >> >> >> >> >> >> >> > So any advice in which direction i need to go > >> >> >> >> >> >> >> > > >> >> >> >> >> >> >> > 2015-08-18 14:14 GMT+03:00 Gregory Farnum > >> >> >> >> >> >> >> > <gfar...@redhat.com>: > >> >> >> >> >> >> >> >> > >> >> >> >> >> >> >> >> From a quick peek it looks like some of the OSDs > are > >> >> >> >> >> >> >> >> missing > >> >> >> >> >> >> >> >> clones > >> >> >> >> >> >> >> >> of > >> >> >> >> >> >> >> >> objects. I'm not sure how that could happen and I'd > >> >> >> >> >> >> >> >> expect > >> >> >> >> >> >> >> >> the > >> >> >> >> >> >> >> >> pg > >> >> >> >> >> >> >> >> repair to handle that but if it's not there's > >> >> >> >> >> >> >> >> probably > >> >> >> >> >> >> >> >> something > >> >> >> >> >> >> >> >> wrong; what version of Ceph are you running? Sam, > is > >> >> >> >> >> >> >> >> this > >> >> >> >> >> >> >> >> something > >> >> >> >> >> >> >> >> you've seen, a new bug, or some kind of config > issue? > >> >> >> >> >> >> >> >> -Greg > >> >> >> >> >> >> >> >> > >> >> >> >> >> >> >> >> On Tue, Aug 18, 2015 at 6:27 AM, Voloshanenko Igor > >> >> >> >> >> >> >> >> <igor.voloshane...@gmail.com> wrote: > >> >> >> >> >> >> >> >> > Hi all, at our production cluster, due high > >> >> >> >> >> >> >> >> > rebalancing > >> >> >> >> >> >> >> >> > ((( > >> >> >> >> >> >> >> >> > we > >> >> >> >> >> >> >> >> > have 2 > >> >> >> >> >> >> >> >> > pgs in > >> >> >> >> >> >> >> >> > inconsistent state... > >> >> >> >> >> >> >> >> > > >> >> >> >> >> >> >> >> > root@temp:~# ceph health detail | grep inc > >> >> >> >> >> >> >> >> > HEALTH_ERR 2 pgs inconsistent; 18 scrub errors > >> >> >> >> >> >> >> >> > pg 2.490 is active+clean+inconsistent, acting > >> >> >> >> >> >> >> >> > [56,15,29] > >> >> >> >> >> >> >> >> > pg 2.c4 is active+clean+inconsistent, acting > >> >> >> >> >> >> >> >> > [56,10,42] > >> >> >> >> >> >> >> >> > > >> >> >> >> >> >> >> >> > From OSD logs, after recovery attempt: > >> >> >> >> >> >> >> >> > > >> >> >> >> >> >> >> >> > root@test:~# ceph pg dump | grep -i incons | > cut -f > >> >> >> >> >> >> >> >> > 1 > >> >> >> >> >> >> >> >> > | > >> >> >> >> >> >> >> >> > while > >> >> >> >> >> >> >> >> > read > >> >> >> >> >> >> >> >> > i; > >> >> >> >> >> >> >> >> > do > >> >> >> >> >> >> >> >> > ceph pg repair ${i} ; done > >> >> >> >> >> >> >> >> > dumped all in format plain > >> >> >> >> >> >> >> >> > instructing pg 2.490 on osd.56 to repair > >> >> >> >> >> >> >> >> > instructing pg 2.c4 on osd.56 to repair > >> >> >> >> >> >> >> >> > > >> >> >> >> >> >> >> >> > /var/log/ceph/ceph-osd.56.log:51:2015-08-18 > >> >> >> >> >> >> >> >> > 07:26:37.035910 > >> >> >> >> >> >> >> >> > 7f94663b3700 > >> >> >> >> >> >> >> >> > -1 > >> >> >> >> >> >> >> >> > log_channel(cluster) log [ERR] : deep-scrub 2.490 > >> >> >> >> >> >> >> >> > > >> >> >> >> >> >> >> >> > > >> >> >> >> >> >> >> >> > > f5759490/rbd_data.1631755377d7e.00000000000004da/head//2 > >> >> >> >> >> >> >> >> > expected > >> >> >> >> >> >> >> >> > clone > >> >> >> >> >> >> >> >> > > >> >> >> >> >> >> >> >> > > >> >> >> >> >> >> >> >> > > 90c59490/rbd_data.eb486436f2beb.0000000000007a65/141//2 > >> >> >> >> >> >> >> >> > /var/log/ceph/ceph-osd.56.log:52:2015-08-18 > >> >> >> >> >> >> >> >> > 07:26:37.035960 > >> >> >> >> >> >> >> >> > 7f94663b3700 > >> >> >> >> >> >> >> >> > -1 > >> >> >> >> >> >> >> >> > log_channel(cluster) log [ERR] : deep-scrub 2.490 > >> >> >> >> >> >> >> >> > > >> >> >> >> >> >> >> >> > > >> >> >> >> >> >> >> >> > > fee49490/rbd_data.12483d3ba0794b.000000000000522f/head//2 > >> >> >> >> >> >> >> >> > expected > >> >> >> >> >> >> >> >> > clone > >> >> >> >> >> >> >> >> > > >> >> >> >> >> >> >> >> > > >> >> >> >> >> >> >> >> > > f5759490/rbd_data.1631755377d7e.00000000000004da/141//2 > >> >> >> >> >> >> >> >> > /var/log/ceph/ceph-osd.56.log:53:2015-08-18 > >> >> >> >> >> >> >> >> > 07:26:37.036133 > >> >> >> >> >> >> >> >> > 7f94663b3700 > >> >> >> >> >> >> >> >> > -1 > >> >> >> >> >> >> >> >> > log_channel(cluster) log [ERR] : deep-scrub 2.490 > >> >> >> >> >> >> >> >> > > >> >> >> >> >> >> >> >> > > >> >> >> >> >> >> >> >> > > a9b39490/rbd_data.12483d3ba0794b.00000000000037b3/head//2 > >> >> >> >> >> >> >> >> > expected > >> >> >> >> >> >> >> >> > clone > >> >> >> >> >> >> >> >> > > >> >> >> >> >> >> >> >> > > >> >> >> >> >> >> >> >> > > fee49490/rbd_data.12483d3ba0794b.000000000000522f/141//2 > >> >> >> >> >> >> >> >> > /var/log/ceph/ceph-osd.56.log:54:2015-08-18 > >> >> >> >> >> >> >> >> > 07:26:37.036243 > >> >> >> >> >> >> >> >> > 7f94663b3700 > >> >> >> >> >> >> >> >> > -1 > >> >> >> >> >> >> >> >> > log_channel(cluster) log [ERR] : deep-scrub 2.490 > >> >> >> >> >> >> >> >> > > >> >> >> >> >> >> >> >> > > >> >> >> >> >> >> >> >> > > bac19490/rbd_data.1238e82ae8944a.000000000000032e/head//2 > >> >> >> >> >> >> >> >> > expected > >> >> >> >> >> >> >> >> > clone > >> >> >> >> >> >> >> >> > > >> >> >> >> >> >> >> >> > > >> >> >> >> >> >> >> >> > > a9b39490/rbd_data.12483d3ba0794b.00000000000037b3/141//2 > >> >> >> >> >> >> >> >> > /var/log/ceph/ceph-osd.56.log:55:2015-08-18 > >> >> >> >> >> >> >> >> > 07:26:37.036289 > >> >> >> >> >> >> >> >> > 7f94663b3700 > >> >> >> >> >> >> >> >> > -1 > >> >> >> >> >> >> >> >> > log_channel(cluster) log [ERR] : deep-scrub 2.490 > >> >> >> >> >> >> >> >> > > >> >> >> >> >> >> >> >> > > >> >> >> >> >> >> >> >> > > 98519490/rbd_data.123e9c2ae8944a.0000000000000807/head//2 > >> >> >> >> >> >> >> >> > expected > >> >> >> >> >> >> >> >> > clone > >> >> >> >> >> >> >> >> > > >> >> >> >> >> >> >> >> > > >> >> >> >> >> >> >> >> > > bac19490/rbd_data.1238e82ae8944a.000000000000032e/141//2 > >> >> >> >> >> >> >> >> > /var/log/ceph/ceph-osd.56.log:56:2015-08-18 > >> >> >> >> >> >> >> >> > 07:26:37.036314 > >> >> >> >> >> >> >> >> > 7f94663b3700 > >> >> >> >> >> >> >> >> > -1 > >> >> >> >> >> >> >> >> > log_channel(cluster) log [ERR] : deep-scrub 2.490 > >> >> >> >> >> >> >> >> > > >> >> >> >> >> >> >> >> > > >> >> >> >> >> >> >> >> > > c3c09490/rbd_data.1238e82ae8944a.0000000000000c2b/head//2 > >> >> >> >> >> >> >> >> > expected > >> >> >> >> >> >> >> >> > clone > >> >> >> >> >> >> >> >> > > >> >> >> >> >> >> >> >> > > >> >> >> >> >> >> >> >> > > 98519490/rbd_data.123e9c2ae8944a.0000000000000807/141//2 > >> >> >> >> >> >> >> >> > /var/log/ceph/ceph-osd.56.log:57:2015-08-18 > >> >> >> >> >> >> >> >> > 07:26:37.036363 > >> >> >> >> >> >> >> >> > 7f94663b3700 > >> >> >> >> >> >> >> >> > -1 > >> >> >> >> >> >> >> >> > log_channel(cluster) log [ERR] : deep-scrub 2.490 > >> >> >> >> >> >> >> >> > > >> >> >> >> >> >> >> >> > > >> >> >> >> >> >> >> >> > > 28809490/rbd_data.edea7460fe42b.00000000000001d9/head//2 > >> >> >> >> >> >> >> >> > expected > >> >> >> >> >> >> >> >> > clone > >> >> >> >> >> >> >> >> > > >> >> >> >> >> >> >> >> > > >> >> >> >> >> >> >> >> > > c3c09490/rbd_data.1238e82ae8944a.0000000000000c2b/141//2 > >> >> >> >> >> >> >> >> > /var/log/ceph/ceph-osd.56.log:58:2015-08-18 > >> >> >> >> >> >> >> >> > 07:26:37.036432 > >> >> >> >> >> >> >> >> > 7f94663b3700 > >> >> >> >> >> >> >> >> > -1 > >> >> >> >> >> >> >> >> > log_channel(cluster) log [ERR] : deep-scrub 2.490 > >> >> >> >> >> >> >> >> > > >> >> >> >> >> >> >> >> > > >> >> >> >> >> >> >> >> > > e1509490/rbd_data.1423897545e146.00000000000009a6/head//2 > >> >> >> >> >> >> >> >> > expected > >> >> >> >> >> >> >> >> > clone > >> >> >> >> >> >> >> >> > > >> >> >> >> >> >> >> >> > > >> >> >> >> >> >> >> >> > > 28809490/rbd_data.edea7460fe42b.00000000000001d9/141//2 > >> >> >> >> >> >> >> >> > /var/log/ceph/ceph-osd.56.log:59:2015-08-18 > >> >> >> >> >> >> >> >> > 07:26:38.548765 > >> >> >> >> >> >> >> >> > 7f94663b3700 > >> >> >> >> >> >> >> >> > -1 > >> >> >> >> >> >> >> >> > log_channel(cluster) log [ERR] : 2.490 deep-scrub > >> >> >> >> >> >> >> >> > 17 > >> >> >> >> >> >> >> >> > errors > >> >> >> >> >> >> >> >> > > >> >> >> >> >> >> >> >> > So, how i can solve "expected clone" situation by > >> >> >> >> >> >> >> >> > hand? > >> >> >> >> >> >> >> >> > Thank in advance! > >> >> >> >> >> >> >> >> > > >> >> >> >> >> >> >> >> > > >> >> >> >> >> >> >> >> > > >> >> >> >> >> >> >> >> > _______________________________________________ > >> >> >> >> >> >> >> >> > ceph-users mailing list > >> >> >> >> >> >> >> >> > ceph-users@lists.ceph.com > >> >> >> >> >> >> >> >> > > >> >> >> >> >> >> >> >> > > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > >> >> >> >> >> >> >> >> > > >> >> >> >> >> >> >> > > >> >> >> >> >> >> >> > > >> >> >> >> >> >> > > >> >> >> >> >> >> > > >> >> >> >> >> > > >> >> >> >> >> > > >> >> >> >> > > >> >> >> >> > > >> >> >> > > >> >> >> > > >> >> > > >> >> > > >> > > >> > > > > > >
_______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
