No, you wouldn’t need to re-replicate the whole disk for a single bad sector. The way to deal with that if the object is on the primary is to remove the file manually from the OSD’s filesystem and perform a repair of the PG that holds that object. This will copy the object back from one of the replicas.
David On Nov 17, 2013, at 10:46 PM, Chris Dunlop <ch...@onthe.net.au> wrote: > Hi David, > > On Fri, Nov 15, 2013 at 10:00:37AM -0800, David Zafman wrote: >> >> Replication does not occur until the OSD is “out.” This creates a new >> mapping in the cluster of where the PGs should be and thus data begins to >> move and/or create sufficient copies. This scheme lets you control how and >> when you want the replication to occur. If you have plenty of space and you >> aren’t going to replace the drive immediately, just mark the OSD “down" AND >> “out.". If you are going to replace the drive immediately, set the “noout” >> flag. Take the OSD “down” and replace drive. Assuming it is mounted in the >> same place as the bad drive, bring the OSD back up. This will replicate >> exactly the same PGs the bad drive held back to the replacement drive. As >> was stated before don’t forget to “ceph osd unset noout" >> >> Keep in mind that in the case of a machine that has a hardware failure and >> takes OSD(s) down there is an automatic timeout which will mark them “out" >> for unattended operation. Unless you are monitoring the cluster 24/7 you >> should have enough disk space available to handle failures. >> >> Related info in: >> >> http://ceph.com/docs/master/rados/troubleshooting/troubleshooting-osd/ >> >> David Zafman >> Senior Developer >> http://www.inktank.com > > > Are you saying, if a disk suffers from a bad sector in an object > for which it's primary, and for which good data exists on other > replica PGs, there's no way for ceph to recover other than by > (re-)replicating the whole disk? > > I.e., even if the disk is able to remap the bad sector using a > spare, so the disk is ok (albeit missing a sector's worth of > object data), the only way to recover is to basically blow away > all the data on that disk and start again, replicating > everything back to the disk (or to other disks)? > > Cheers, > > Chris. _______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
