On Mon, Apr 9, 2012 at 11:16, Sage Weil <sage@xxxxxxxxxxxx> wrote: > One thing we need to keep in mind here is that the individual disks are > placed in the CRUSH hierarchy based on the host/rack/etc location in the > datacenter. Moving disk around arbitrarily will break the placement > constraints if that position isn't also changed. Yeah, the location will have to be updated. I tend to think disks *will* move, and it's better to cope with it than to think it won't happen. All you need is a simple power supply/mobo/raid controller/nic/etc failure, if there's any free slots anywhere it's probably better to plug the disks in there than waiting for a replacement part. I'm working under the assumption that it's better to "just bring them up" rather than having an extended osd outage or claiming the osd as lost. Updating the new location for the osd could be something we do even at every osd start -- it's a nop if the location is the same as the old one. And we can say the host knows where it is, and that information is available in /etc or /var/lib/ceph. I'll come back to this once it's a little bit more concrete; I'd rather not make speculative changes, until I can actual trigger the behavior in a test bench. -- 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
