Any rsync experts here? I have a tricky problem. I thought I was fairly adept with rsync but this one has me stumped.

My backup scheme is a 1:1 snapshot of my home dir, updated hourly, to 4TD spinning rust. The thing is about 500 GB. Just a simple copy, -ua --delete.

Hourly a bash script creates a new year/month/day/HOUR folder, then does the classic hard link/rsync hack of copying the previous hour's folder to the new HOUR using hard links, then rsync updates the new HOUR from the snapshot (rsync unlinks before copying). The result is that only files that have changed are copied, the rest (99.999% usually) are just hard links.

(On different scheds I prune these at 30 days to one saved per day, blah blah, immaterial here.)

I've got two years of this, consuming ~3TB of disk.

MY PROBLEM/QUESTION:

I need to move these directories and files from an ext4 drive in Debian box A, to a zfs system in FreeBSD box B.

The problem is that all that rsync can do is copy a hard-linked file, not reproduce the directory relationships to the underlying inodes; rsync is magical but not that magical.

Can anyone think of a way to move this big blob of interrelated files and hard links?