[pve-devel] ceph replication speed

[Martin Maurer]

> we just notices a big write speed difference when replication size differs:
> 
> size = 2: 100MB/s
> size = 3:  60MB/s

After removing one OSD per node (now we have only 1 OSD per host, Seagate Constellation ES.3 4TB, journal on the same), we have:

size = 2: 55 MB/s
size = 3: 41 MB/s

I will add three OSDs on each host - (as soon as I got the disks here) and I expect more speed.
But the difference between the replication of 2 or 3 is not totally clear to me.

Martin