UNable to import ZFS volume

[phimmerich]

I upgraded the hard drives in my freenas system from 2 x 2 tb to 2 x 8tb. I replaced the disk one at a time doing a resilver after each.
Somehow i managed to mess that up and i am missing the data that was on those 2tb drives.
I still have both of the old drives available. When i tried to reverse the process by simply replacing both new drives with the old drives, the old volume was not detected.
I can attach one of the old drives but i am unable to import the volume.
I know that this post misses a lot of data to properly diagnose and help but i dont exactly know where to start.
gpart show :
=> 40 31702960 da0 GPT (15G)
40 1024 1 bios-boot (512K)
1064 31701928 2 freebsd-zfs (15G)
31702992 8 - free - (4.0K)

=> 40 937703008 ada0 GPT (447G)
40 88 - free - (44K)
128 4194304 1 freebsd-swap (2.0G)
4194432 933508608 2 freebsd-zfs (445G)
937703040 8 - free - (4.0K)

=> 40 15628053088 ada1 GPT (7.3T)
40 88 - free - (44K)
128 4194304 1 freebsd-swap (2.0G)
4194432 15623858688 2 freebsd-zfs (7.3T)
15628053120 8 - free - (4.0K)

=> 40 3907029088 ada2 GPT (1.8T)
40 88 - free - (44K)
128 4194304 1 freebsd-swap (2.0G)
4194432 3902834688 2 freebsd-zfs (1.8T)
3907029120 8 - free - (4.0K)

=> 40 15628053088 ada3 GPT (7.3T)
40 88 - free - (44K)
128 4194304 1 freebsd-swap (2.0G)
4194432 15623858688 2 freebsd-zfs (7.3T)
15628053120 8 - free - (4.0K)


ada2 is the drive with the missing data, however zfs status shows the volume that used to be on that drive.

I know its a mess and I did some extensive research online with no luck