hi all,

Been using Unraid since around 2010 and its been rock solid. Just need to ping a few things off the more intelligent people out there as I don't really do major changes to hardware often and there is only so much reading you can do in preparation, especially when moving to a new major version.

Goal:

Move my 5 unraid data disks from my existing Unraid 6.12 server (TowerA_6) to a new server running Unraid 7 (TowerB_7). I would rather NOT copy the data to "new" disks as this involves me first having to BUY a lot of large (14+ TB) drives. So my goal is to MOVE the physical disks over to the new server.

I have a PRO licence on my TowerA_6 server. I currently have a TRIAL Unraid 7 on a fresh USB as I intend to setup dockers and apps from fresh to tidy up some old legacy stuff. I will then MIGRATE my PRO licence to the new server. So for all intents and purposes, lets say TowerB_7 is a fresh Unraid 7 install with nothing else, no parity and no data disks in it.

Questions:

1) If I take a few data disks (e.g Disk1 and Disk2) from TowerA_6 and put those into TowerB_7. Then fire up unraid, I understand these will show as unmounted/unallocated. If i setup the new Unraid 7 array (4 devices) with NO parity disk assigned, but just assign the two disks as Disk1 and Disk2 - will i be able to start the array without unraid wanting to format the disks?

2) Assuming the answer to the above is "YES" (the data will be preserved and Disk1 and Disk2 will NOT be formatted), if I now allocated a NEW precleared disk as parity to the array, again will the data on Disk1 and Disk2 remain preserved? Is there any specific check box or settings I need to be aware of to ensure no data is lost?

3) Can I then just expand the array size and again physically move over data Disk3, Disk4 and Disk5 from TowerA_6 to TowerB_7 without any loss of data? VERY IMPORTANT - would I first need to unallocated the PARITY drive on TowerB_7 before taking this step? (would Unraid think it needs to clear Disk3, Disk4 and Disk5 due to an invalid parity?)

Notes:

I will only ever run 1 parity drive

All disks from TowerA_6 are in XFS format

I will continue to use XFS when i setup the new array on TowerB_7 (specifically when i expand the array)

I'm sorry as some of this is likely REALLY stupid but i need to make sure im not about to make some stupid mistake and delete a bunch of data!

Appreciate any help and assistance you can provide.

Edited October 24, 2025Oct 24 by monza
spelling

3 hours ago, monza said:

NO parity disk assigned, but just assign the two disks as Disk1 and Disk2 - will i be able to start the array without unraid wanting to format the disks?

Yes.

3 hours ago, monza said:

if I now allocated a NEW precleared disk as parity to the array, again will the data on Disk1 and Disk2 remain preserved?

Yes.

3 hours ago, monza said:

Can I then just expand the array size and again physically move over data Disk3, Disk4 and Disk5 from TowerA_6 to TowerB_7 without any loss of data?

Not with parity assigned; any new disk will be cleared.

thank you JorgeB.

Bonus question, is there anything special I need to do with my existing Parity disk from TowerA_6 to REPURPOSE it for use as a data disk in TowerB_7?

If I just moved that disk to TowerB_7 and assigned it as a data disk slot, would unraid just format it and have it ready for me to use it? For some reason in my head i am thinking it would cause some issues as TowerB_7 would see it as as being previously used for Parity and that might cause some issues.

again, thank you for the prompt response Jorge, i feel a lot happier moving into this now.

Just now, monza said:

If I just moved that disk to TowerB_7 and assigned it as a data disk slot, would unraid just format it and have it ready for me to use it? For some reason in my head i am thinking it would cause some issues as TowerB_7 would see it as as being previously used for Parity and that might cause some issues.

Should be no problem. Assuming the new system already has parity then that disk will be Cleared when you add it as a new data drive. After the Clear has finished you will then need to format it in Unraid to your desired file system type to get it ready to be used.

ok great, that sounds like what I had thought would/should happen :)

I think I'm set now, once ive get the physical data disks moved over, ill then assign the parity drive LAST. Then i can setup my user shares again which ill likely replicate based on my 'old' server config - hoping that is straight forward too and doesn't mess anything up?

e.g i have a "Movies" user share that spanned disks 1, 2 and 3.

The folder structure on each of those disks was:

/Movies

--> 01BluRay

--> 02UHD4K

So I can just go ahead and create the "Movies" user share on TowerB_7 and it wouldn't do anything funky even though that Movies 'folder' exists on the data disks?

Edited October 24, 2025Oct 24 by monza
typo

It's not a problem.

thank you both for your assistance

I have been pondering these very questions. thanks all.