move OSDs disks between hosts

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.