RIP Ceph.
> On 11 Apr 2016, at 23:42, Allen Samuels <[email protected]> wrote: > > RIP ext4. > > > Allen Samuels > Software Architect, Fellow, Systems and Software Solutions > > 2880 Junction Avenue, San Jose, CA 95134 > T: +1 408 801 7030| M: +1 408 780 6416 > [email protected] > > >> -----Original Message----- >> From: [email protected] [mailto:ceph-devel- >> [email protected]] On Behalf Of Sage Weil >> Sent: Monday, April 11, 2016 2:40 PM >> To: [email protected]; [email protected]; ceph- >> [email protected]; [email protected] >> Subject: Deprecating ext4 support >> >> Hi, >> >> 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. >> >> Why: >> >> 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 *could* invest a ton of time rewriting this to fix, but it only affects >> ext4, >> which we never recommended, and we plan to deprecate FileStore once >> BlueStore is stable anyway, so it seems like a waste of time that would be >> better spent elsewhere. >> >> Also, by dropping ext4 test coverage in ceph-qa-suite, we can significantly >> improve time/coverage for FileStore on XFS and on BlueStore. >> >> The long file name handling is problematic anytime someone is storing rados >> objects with long names. The primary user that does this is RGW, which >> means any RGW cluster using ext4 should recreate their OSDs to use XFS. >> Other librados users could be affected too, though, like users with very long >> rbd image names (e.g., > 100 characters), or custom librados users. >> >> How: >> >> To make this change as visible as possible, the plan is to make ceph-osd >> refuse to start if the backend is unable to support the configured max >> object name (osd_max_object_name_len). The OSD will complain that ext4 >> cannot store such an object and refuse to start. A user who is only using >> RBD might decide they don't need long file names to work and can adjust >> the osd_max_object_name_len setting to something small (say, 64) and run >> successfully. They would be taking a risk, though, because we would like >> to stop testing on ext4. >> >> Is this reasonable? If there significant ext4 users that are unwilling to >> recreate their OSDs, now would be the time to speak up. >> >> Thanks! >> sage >> >> -- >> To unsubscribe from this list: send the line "unsubscribe ceph-devel" in >> the body of a message to [email protected] >> More majordomo info at http://vger.kernel.org/majordomo-info.html > _______________________________________________ > ceph-users mailing list > [email protected] > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com _______________________________________________ ceph-users mailing list [email protected] http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
