Hello all, hope all is well. Im not sure if this question has been asked before. Im sure it has and i looked through the forum but i couldnt seem to find one, and if this is in the wrong section please guide me to the right one lol. But to my question. i have 8 4tb hdds set up in a raidz1 configuration with roughly 6 tb of data that i do not want to lose. im wanting to transfer all my hdds to another smaller enclosure with a different mobo and most likely a cpu. its to save space in my apartment. if i transfer the hdds, will i need to put them back in the order they were configured or can i just transfer them over and TN will just solve the order issue in the software? im savy enough to setup TN with guides etc. i just dont have a lot of experience with it. any help would be appreciated. thanks in advance.
Welcome to the forums! You may put them back in any order.
Do you have at least one backup of this 6 TB of data on a different physical hardware and/or location? If not: Congratulations. You’ve just lost all your data.
(I’m being hyperbolic for a reason.)
Correct.
TrueNAS uses the GPTID or PARTUUID for the member devices (partitions) in the pool’s vdevs. This means it will not care what ports you plug your drives into or what motherboard/system they are physically migrated to. (You must export your pool before you do any migration or disconnections.)
actually one of the reasons why im looking to transfer the hdds to a smaller case is because im looking to make two NAS and have one backing up the other. i just dont have room to have multiple “server” cases lol. quick question to add. what would be the fastest way to transfer data between the two? if my nomenclature isnt correct im open to corrections so i can get more experience and learn.
The most “replica” way to do it is to use ZFS replication.
Hm i would suggest before you do any of this, that you have a backup to a separate storage device. Once you have done that, THEN you can attempt to make that switch.
Sure you could possibly do it and nothing happens. But why take that chance? I’ve made a few mistakes in past that i didn’t think would occur, but i always had a backup to fall back on. Do you?
Don’t wait till you lose your data before you learn the hardway is my advice. not to be mean, but that’s just the hard facts.
Also remember later when you start truenas web ui and you reach the pool section, be sure to select IMPORT pool. It will say it detected your drives have some pools, and ask you what to do with them. Select import.
This is what i did when i had factory reset, my pools remained in tact so i merely recovered by importing the pools to the new truenas install and i managed to recover my data without having to resort to my backups. that saved me a lot of time and effort.
Fyi this is not a substitute for a backup as anything could potentially go wrong. Just saying.
Should. If you forget you can force import.
The fastest way is local replication between two pools attached to the same system… then move a pool.
The easiest fast way is to use replication over the network, which is also how the backups should work.
I knew someone would catch that, but I left it anyways, since when it comes to “best practices”, I tend to replace “should” with “must” to scare new users into adopting the best habits.
Example: “If you want to preserve your invaluable, irreplaceable data, then you must create at least one backup of it.” 
yet a lot of people seem to not think or use it till disaster strikes. but by then too late 
the backups are meant to be in place BEFORE anything happens. o well 