Hello, On Tue, 12 Apr 2016 09:00:19 +0200 Michael Metz-Martini | SpeedPartner GmbH wrote: > Hi, > > Am 11.04.2016 um 23:39 schrieb Sage Weil: > > ext4 has never been recommended, but we did test it. After Jewel is > > out, we would like explicitly recommend *against* ext4 and stop > > testing it. > Hmmm. We're currently migrating away from xfs as we had some strange > performance-issues which were resolved / got better by switching to > ext4. We think this is related to our high number of objects (4358 > Mobjects according to ceph -s). > It would be interesting to see on how this maps out to the OSDs/PGs. I'd guess loads and loads of subdirectories per PG, which is probably where Ext4 performs better than XFS. > > > Recently we discovered an issue with the long object name handling > > that is not fixable without rewriting a significant chunk of > > FileStores filename handling. (There is a limit in the amount of > > xattr data ext4 can store in the inode, which causes problems in > > LFNIndex.) > We're only using cephfs so we shouldn't be affected by your discovered > bug, right? > I don't use CephFS, but you should be able to tell this yourself by doing a "rados -p <poolname> ls" on your data and metadata pools and see the resulting name lengths. However since you have so many objects, I'd do that on a test cluster, if you have one. ^o^ If CephFS is using the same/similar hashing to create object names as it does with RBD images I'd imagine you're OK. Christian -- Christian Balzer Network/Systems Engineer chibi@xxxxxxx Global OnLine Japan/Rakuten Communications http://www.gol.com/ _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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