After reinstallation of PVE, CEPH automatically detects OSD but keeps it as down. To run OSD it is need to:
ceph-volume lvm activate –all
If you used ceph-deploy and/or ceph-disk to set up these OSDs (that is, if they are stored on labeled GPT partitions such that upstart is automagically starting up the ceph-osd daemons for you without you putting anythign in /etc/fstab to manually mount the volumes) then all of this should be plug and play for you--including step #3. By default, the startup process will 'fix' the CRUSH hierarchy position based on the hostname and (if present) other positional data configured for 'crush location' in ceph.conf. The only real requirement is that both the osd data and journal volumes get moved so that the daemon has everything it needs to start up.
if you don't have a separate (shared) journal device, you can just down and out the OSD and physically move it from one host to another. (hot-)plugging it in should automatically start the OSD service on the new host, and you can mark the osd as "in" on the GUI. if you have a separate journal device only used for the particular osd, you can move it together with the OSD and it should work as well. if you have a shared journal device, you might be able to move all the OSDs using it and the journal, all at the same time - I have never tried this though. if you only want to move one of several OSDs sharing a journal, this is AFAIK not possible, and you need to actually remove it and create a new OSD from scratch on the new host, using the moved disk.