How to choose pg_num while creating pool in ceph

Question

I have established a Proxmox cluster comprising 5 nodes, with 4 OSDs added to each node. Currently, I am uncertain about the process of creating a pool and the recommended pg_num for this pool creation. Any suggestions?

Answer 1

Choosing the right pg_num value is crucial because it can't be figured out automatically. Here's a simple guide:

• If you have less than 5 OSDs, set pg_num to 128.
• For 5 to 10 OSDs, use pg_num 512.
• If you have 10 to 50 OSDs, set pg_num to 1024.

If you've got more than 50 OSDs, you need to understand the details and calculate the pg_num value on your own. Use the pgcalc tool to help with this calculation.