I believe the third party back up is a windows level daily back up. it looks like the diff one doesn't cooperate with the third party one. We never had a chance to retore the third party backup. Since the diff backup failed (due to not enough disk space), I couldn't retrieve the lsn info. I'm a newbie. It could be a silly question. Shouldn't there be a cooperation working between the third party backup and the diff backup. To me, there's no conversation between the two.