On 01/29/2018 07:26 PM, Nico Schottelius wrote:
Hey Wido,
[...]
Like I said, latency, latency, latency. That's what matters. Bandwidth
usually isn't a real problem.
I imagined that.
What latency do you have with a 8k ping between hosts?
As the link will be setup this week, I cannot tell yet.
However, currently we have on a 65km link with ~2ms latency.
In our data center, we currently have ~0.4 ms latency.
(both 8k pings).
0.4ms is already high for a 8k packet over 10GbE, you should see about
0.2ms.
Although the difference between 0.4ms and 0.2ms is just, yes, 0.2ms it's
a 100% increase and does half the amount I/O you can do in a second.
Latency is crucial with RBD performance and you shouldn't take that lightly.
RBD mirroring is async and I'd like to recommend you to look into it.
Keep the two Ceph cluster separate ones and keep it simple.
Wido
Do you see similar latencies in your setup?
Best,
Nico
--
Modern, affordable, Swiss Virtual Machines. Visit www.datacenterlight.ch
_______________________________________________
ceph-users mailing list
ceph-users@xxxxxxxxxxxxxx
http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
