I realize the switch might do something different. I have a Cisco SG300 and a Brocade ICX6450 at my disposal. Haven't really looked at that yet since I don't have the destination NAS yet, but...Because you do get it. This part is correct. The hash used by the switch, though, may be different, so you have a complex multivariable problem here, both "will the FreeBSD hash do the right thing" and then "will the switch hash also do the right thing."
But this, though, this is the problem I see. (Assuming you get the hash thing working. Which is a workable problem.)
Your idea isn't really possible without some sort of multiple snapshot scenario. If you have multiple datasets, and you snap each one, then yes, this is theoretically possible, but I hope it is obvious that this is something you'd have to be doing by hand.
Finally got word my FreeNAS Mini XL shipped. I should have it tomorrow.
Yes, I think I can get the bulk of my pool into two or three large snapshots. I was going to try to send them all over and wanted to try to leverage LACP to trim the number of hours/days required to ship my data over.
I'll try two or three different snapshot sync destination IP addresses and see what happens.
More of an exercise.Do you have existing snapshots or other ZFS-y things you're trying to preserve on the pool? Or are you just looking to move files from pool A to pool B?