On Thursday, July 10, 2014, Erik Logtenberg <erik at logtenberg.eu> wrote: > > > Yeah, Ceph will never voluntarily reduce the redundancy. I believe > > splitting the "degraded" state into separate "wrongly placed" and > > "degraded" (reduced redundancy) states is currently on the menu for > > the Giant release, but it's not been done yet. > > That would greatly improve the accuracy of ceph's status reports. > > Does ceph currently know about the difference of these states well > enough to be smart with prioritizing? Specifically, if I add an OSD and > ceph starts moving data around, but during that time an other OSD fails; > is ceph smart enough to quickly prioritize reduplicating the lost copies > before continuing to move data around (that was still perfectly > duplicated)? > I believe that when choosing the next PG to backfill, OSDs prefer PGs which are undersized. But it won't stop replicating a PG if one goes undersized mid-process, and it's not a guarantee anyway because backfill is distributed over the cluster, but the decisions have to be made locally. (So a backfilling OSD which has no undersized PGs might beat out an OSD with undersized PGs to get the "reservation".) -Greg -- Software Engineer #42 @ http://inktank.com | http://ceph.com -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.ceph.com/pipermail/ceph-users-ceph.com/attachments/20140710/17bf2c36/attachment.htm>
 |