[ceph-users] Ceph Minimum Cluster Install (ARM)

[Garg, Pankaj]

Hi,
I am trying to get a very minimal Ceph cluster up and running (on ARM) and I'm wondering what is the smallest unit that I can run rados-bench on ?
Documentation at (http://ceph.com/docs/next/start/quick-ceph-deploy/) seems to refer to 4 different nodes. Admin Node, Monitor Node and 2 OSD only nodes.

Can the Admin node be an x86 machine even if the deployment is ARM based?

Or can the Admin Node and Monitor node co-exist.

Finally, I'm assuming I can get by with only 1 independent OSD node.

If that's possible, I can get by with 2 ARM systems only. Can someone please shed some light on whether this will work?

Thanks
Pankaj

[Christian Balzer]

Post by Garg, Pankaj
Hi,
I am trying to get a very minimal Ceph cluster up and running (on ARM)
and I'm wondering what is the smallest unit that I can run rados-bench
on ? Documentation at
(http://ceph.com/docs/next/start/quick-ceph-deploy/) seems to refer to 4
different nodes. Admin Node, Monitor Node and 2 OSD only nodes.
Can the Admin node be an x86 machine even if the deployment is ARM based?
Or can the Admin Node and Monitor node co-exist.
Finally, I'm assuming I can get by with only 1 independent OSD node.
If that's possible, I can get by with 2 ARM systems only. Can someone
please shed some light on whether this will work?

You can do everything on one node even (need to set replica size to 1).

However that will not realistically reflect reality at all and any
benchmarks will be skewed (as always with very small clusters).

In addition to that your systems need to be fast enough, meaning CPU for
OSD and MON, fast storage for MON(OS) and sufficient RAM to handle
everything.

Again, learning some things about Ceph is feasible with a minimal cluster,
but drawing conclusions about performance with what you have at hand will
be tricky.

Lastly, Ceph can get very compute intense (OSDs, particularly with small
I/Os), so I'm skeptical that ARM will cut the mustard.

Christian