[ceph-users] Re: Pool on limited number of OSDs

On 2/18/20 6:56 PM, Jacek Suchenia wrote:

Hello

I have a cluster, (Nautilus 14.2.4) where one pool I'd like to keep on a dedicated OSDs. So I setup a rule that covers *3* dedicated OSDs (using device classes) and assigned it to pool with replication factor *3*. Only 10% PGs were assigned and rebalanced, where rest of them stuck in *undersized* state.

Can you share the rule and some snippets of the CRUSHMap? Wido

What mechanism prevents CRUSH algorithm to assign the same set of OSDs to all PGs in a pool? How can I control it?

Jacek