db_rsyncs is not its own filesystem, just a sub-folder under /zpool, so I don’t know if this will tell you much…
On the source server, STORE50B
[root@store50b zpool0]# zfs list -tall
NAME USED AVAIL REFER MOUNTPOINT
zpool0 10.9T 3.50T 10.9T /zpool0
On the dest server, STORE50A
[root@store50a ~]# zfs list -tall
NAME USED AVAIL REFER MOUNTPOINT
zpool0 4.86T 9.50T 4.86T /zpool0
Let’s stand down for a couple of days on this while I monitor the behavior some more and explore a possible theory I have about what’s happening.