On 27/04/2013, at 06.45, Xiaopong Tran <xiaopong.tran@xxxxxxxxx> wrote: > On 04/27/2013 01:07 AM, Anders Saaby wrote: >> >>> How many OSDs per machine do you have and how much memory do you have per machine? >> >> 12 OSD's per machine. A bit over 1GB memory per OSD. (16GB per machine) > > Try more. If you have a large-ish cluster, with many OSDs, and if you > have large PGs, when one or more OSDs go down (for different reasons, > a crash, a disk failure, etc), Ceph will start to remap and rebalance, > memory usage per OSD can easily balloon to GBs per OSD. I take it, you mean more memory? Is there a way to calculate OSD memory requirements based on pg_num and/or number of OSDs? > When this happens, and if you don't have enough memory, the > OSD processes might get OOM-killed, and you'll get into a > vicious cycle. Right. regards, Anders -- 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
