[ceph-users] issues with object-map in benji

Hello, Lately, we upgraded Ceph to version 15.2.4 and shortly after that we had a blackout, which caused a restart of all servers at once (BTW, Ceph did not come up well itself). Since then we were receiving lots of complaints about problems with "object-maps" with every benji backup (tool for differential backups of RBD images). So, I turned on "exclusive-lock" and "fast-diff" and rebuilt object-maps for all RBD images. Since then I am receiving the following message for every RBD image backup: 2020-08-24T06:25:10.451+0200 7f0b857fa700 -1 librbd::object_map::InvalidateRequest: 0x7f0b8000a690 invalidating object map in-memory 2020-08-24T06:25:10.451+0200 7f0b857fa700 -1 librbd::object_map::InvalidateRequest: 0x7f0b8000a690 invalidating object map on-disk 2020-08-24T06:25:10.451+0200 7f0b857fa700 -1 librbd::object_map::InvalidateRequest: 0x7f0b8000a690 should_complete: r=0 I am not sure whether it indicates some real problem limiting the functionality of the backups, or whether it is just natural part of the process. Is it a problem of Ceph and the unexpected blackout causing some corruption, or a problem of Benji and some new feature/issue of Ceph version 15? I wonder whether the object-maps were used before, since there were never any reports about any problems of this kind, and even the features mentioned above were (probably?) never turned on before (so there were no object maps at all?). I am quite confused. Thanks for any explanation, Pavel