On Fri, 15 Jun 2012, Mark Nelson wrote: > On 06/15/2012 04:51 AM, Wido den Hollander wrote: > > Hi, > > > > On 15-06-12 07:52, Stefan Priebe - Profihost AG wrote: > > > Hello list, > > > > > > i read somewhere that the mon has "special" disk access patterns - even > > > though it does not write much data. > > > > "special"? Where did you read that? The monitor has about 1 ~ 2GB of > > storage. > > > > So if your monitor has something like 4GB ~ 8GB of RAM, your kernel > > should cache almost all your monitor data. > > > > I think at some point someone mentioned to me that the mon can cause a lot of > syncs, so running them on the OSDs without syncfs might be detrimental. For > the majority of our internal performance testing I've kept them off the OSDs > just to be sure. Right. The only thing interesting about the mon access pattern is that it calls fsync() a lot when healthy, and will call syncfs() or sync() during recovery. sage -- 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
