Ceph » CephFS

Adding additional data pools via ceph fs add_data_pool is very easy, but once a pool is in use, it is very hard to move data back to the main pool (e.g. for replacing a data pool with another pool with different settings). Right now, the only option is to reset all file attributes recursively and then copy the whole tree to a new directory which is beyond infeasible for large TB- or PB-sized file trees.

It would be great if there were a command for decommissioning data pools. Even if pool decommissioning is too difficult to execute online and would mean a temporary FS downtime or a forced read-only mode for the duration, it would still be incredibly useful.

I have a secondary data pool with only few 100k objects totalling about 14GB, but they are scattered throughout a large-ish 70TB+ file tree which I cannot simply touch and move recursively.