On 04/18/2013 10:12 AM, Emmanuel Lacour wrote:
On Thu, Apr 18, 2013 at 04:19:09PM +0200, Emmanuel Lacour wrote:
1) If you put your journals on the same devices, you are doing 2
writes for every incoming write since we do full data journalling.
Assuming that's the case we are down to 25MB/s.
to reduce this double write overhead, I tried to put the journal on
tmpfs and I got far better performances, nearly equal to the slower
disk. So with low count of osd and low performance osd data drives, the
only way to go seems to put the journal on ssd.
SSD journals definitely help, especially when doing large writes and
targeting high throughput.
If you get a chance, it still may be worth giving 0.60 a try and seeing
if helps at all.
_______________________________________________
ceph-users mailing list
ceph-users@xxxxxxxxxxxxxx
http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
_______________________________________________
ceph-users mailing list
ceph-users@xxxxxxxxxxxxxx
http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
