On Wed, 29 Oct 2014 15:32:57 +0000 Michal Kozanecki wrote: [snip] > With Ceph handling the > redundancy at the OSD level I saw no need for using ZFS mirroring or > zraid, instead if ZFS detects corruption instead of self-healing it > sends a read failure of the pg file to ceph, and then ceph's scrub > mechanisms should then repair/replace the pg file using a good replica > elsewhere on the cluster. ZFS + ceph are a beautiful bitrot fighting > match! > Could you elaborate on that? AFAIK Ceph currently has no way to determine which of the replicas is "good", one such failed PG object will require you to do a manual repair after the scrub and hope that two surviving replicas (assuming a size of 3) are identical. If not, start tossing a coin. Ideally Ceph would have a way to know what happened (as in, it's a checksum and not a real I/O error) and do a rebuild of that object itself.
On an other note, have you done any tests using the ZFS compression? I'm wondering what the performance impact and efficiency are. Christian -- Christian Balzer Network/Systems Engineer ch...@gol.com Global OnLine Japan/Fusion Communications http://www.gol.com/ _______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
