Comment 6 for bug 1885516

I believe this is what happened: this cloud used to be a xenial-ocata using filestore. When it got upgraded to bionic-queens it gained the ability to use bluestore, and the charm started defaulting to bluestore=true. We then expanded the cloud without modifying the charm config, which led to ceph-osd trying to create a bluestore osd in an xfs drive that was really meant to host a filestore osd.

While I agree the charm pretty much tried doing what it was told to, it would be much more user friendly if the unit went into a blocked state when it detects the combination of bluestore=true and the existence of at least one of the osd-devices paths.