Comment by brentjanderson

I looked at getting LSN numbers after an upgrade/cluster replacement, and IIRC restoring from a snapshot emits LSN information into the logs, but it's a bit of of a mixed bag as to whether or not you get the __right__ LSN out the other side. Because the LSN is more a measure of how many bytes have been written within a cluster, it's not something that meaningfully translates to other clusters, unfortunately.