So I've just finished upgrading my home cluster OSDs to bluestore by killing them one by one and then letting backfill happen to "new" OSDs on the same drives. Hooray! One slightly awkward thing I ran into was that even though I had noout set throughout, during the period between removing the old OSD and adding the "new" one, some PGs would of course get remapped (and start generating backfill IO to third party OSDs). This does make sense when you think about it (noout doesn't make the cluster magically remember OSDs that have been removed), but is still an undesirable behaviour. A) Do we currently have a mechanism to tell the cluster "even though I removed this OSD, don't go moving PGs around just yet"? Should we add one? B) Was there a way for me to avoid this by e.g. skipping the "osd rm X" and "osd crush rm osd.X" that I'm currently doing before adding the new OSD that will take the old OSD's ID? John -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
