Ceph » ceph-volume

ceph-volume simple activate --all relies on the presence of json files
in /etc/ceph/osd that was created with ceph-volume simple scan
command.

In a cluster lifecycle, it is very likely an OSD which was deployed with
ceph-disk at some point gets removed or replaced. It means the corresponding
json file in /etc/ceph/osd becomes unrelevant. It makes ceph-volume simple activate --all fails because it tries to mount non existing
partitions.
The idea here is to simply warn the user that the osd described in the
json file doesn't exist anymore and exit properly instead of throwing an
error.