As far as I understand (but please correct me if I am wrong) the problem importing on another OSD is that ceph doesn't automatically then detect that the PG is now available on another OSD. In my case [*] it expects the data from 206, 233 and 250
From what I understand, when you inject a "foreign" PG into the OSD, it will report to the mons that it now has this PG and its objects (at some version) and then the mons/mgrs will often decide it is available, but perhaps misplaced and move it to where it now should reside. And if it is not broken, it will start serve data and/or be the source for backfills if it was the only replica for this PG. Of course I have never had to do this myself, but from what reports here on the maillist have said, I have understood it as being a good way to inject a copy of a PG if you can extract it from an otherwise failed OSD which will not start. -- May the most significant bit of your life be positive.