The problem with non-PLP drives is that Rook-Ceph will insist that its writes get done in a way that is safe wrt power loss.

For regular consumer drives, that means it has to wait for the cache to be flushed, which takes aaaages (milliseconds!!) and that can cause all kinds of issues. PLP drives have a cache that is safe in the event of power loss, and thus Rook-Ceph is happy to write to cache and consider the operation done.

Again, 1Gb network is not a big deal, not using PLP drives could cause issues.

If you don’t need volsync and don’t need ReadWriteMany, just use Longhorn with its builtin backup system and call it a day.