Ceph-pool migration

Hey,

So let’s assume you have created a ceph-pool with HDDS only, but you are thinking about switching to SSDs later, is that possible without any major risks ?

So the idea is, that you create a crush-rule for the SSD device class and say that the pool should use it, afterwards you remove the other crush -rule for the HDD device class from that pool.

What would happen if you do this ? Will the objects transferred to the other devices, or will they get deleted ? Or are they still on the devices but not really accessible anymore, at least from the pool ?

Thanks for you answerers in advance

Why not simply add your new SSD backed pool and migrate your images between your 2 pools ?