Replicas

SpyderVeloce

New Member
Feb 12, 2025
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I recently set up a 5-node Proxmox/Ceph cluster with 10 OSDs each node for a total for 50 nodes (approximately 135TB).

All the nodes have 768GB RAM and a single 72-Core (144 thread) Epyx CPU.

I set the ceph pool size to: 3 and the minimum size: 2.

The performance seemed good and everything was happy in cephland!

The other day I spoke to a ceph consultant and he recommended I change the pool size from 3/2 to 2/1.

He cited several valid points: more usable storage space, faster rebuilds, better performance…

I followed his advice and changed it. The benchmark performance was about the same, but the recovery time when I took a node down was improved.

I really do like the idea of the extra storage space!

So now I am confused whether I should leave it or go back to 3 replicas.



Anyone have any thoughts or compelling reasons I should leave it or change it back?