Move old unraid drives into a new unraid server?

[Terpinol]

TLDR; Is there a way to successfully move array drives from one unraid server into a new unraid server without them interfering with the new array?

 

BACKGROUND: I have an old server box that I installed a trial version of unraid on last month. It has three 4TB data drives in the array (2 data, one parity). Deciding the old server is too anemic, I built a new computer to be my unraid server.  I installed three new 4TB drives in it and configured them similarly as the old server, along with two cache SSDs. Since my old trial license is now expired, I created a new trial license on a new flash drive. All is up and running on the new server and it's configured fine. Now, I'd like to migrate (or just add) the data from the old array into my new array and then add the old 4TB disks to the new array.

 

Is this possible by just adding the 3 old drives as unattached storage and then using something like Krusader to copy the files? Or can I even just attach the drives to the new server and add them to the array directly without having to copy data? I'm also worried that the old parity drive from my old server will try to assert itself as a parity drive in the new server. (The other two drives I'm not as worried about since they were just data disks in the array.)

 

Thx for any helpful advice!

 

[trurl]

1 hour ago, Terpinol said:

add them to the array directly without having to copy data?

https://wiki.unraid.net/Manual/Storage_Management#Reset_the_array_configuration

[Terpinol]

Thanks trurl. Just to be clear, though, in my case I should run New Config on the old server, not the new one, right?  If I choose to "have the system preserve some of the current assignments" will that cause confusion with the new vs. old parity drive? 

[ChatNoir]

On 12/16/2021 at 5:36 AM, Terpinol said:

Just to be clear, though, in my case I should run New Config on the old server, not the new one, right?

Depends.

• Will you keep the old server running ?
• Is your new server already running with Array drives already assigned ?

If you won't keep the old server running and simply want to add the data drive to an existing array, plus add the old parity as a data drive in the new server :

1. on Main the OLD server note what drive is parity, what drives are data
2. on Main the NEW server note what drive is parity, what drives are data
3. on the NEW server, go to Tools / New Config (you might have to stop the Array first)
4. select to KEEP the drives assignements for Array and Pool
5. back to Main, check that the config is still OK
6. add assign the drives from OLD server
7. start the Array but do NOT tick the box saying that the Parity is correct, it is not and will have to be built again
8. it should show your OLD parity drive as needing FORMAT
9. check that it is indeed the correct drive from step #1 and only format that one

If you have any questions or are unsure at any step in the process, come back on the forum.  

[Terpinol]

1 hour ago, ChatNoir said:

Will you keep the old server running ?

No. My plan is to migrate only the mechanical drives into the new box. The old box will be retired. 

 

1 hour ago, ChatNoir said:

Is your new server already running with Array drives already assigned ?

Yes it is. 

 

Thanks for the detailed advice, ChatNoir, much appreciated! The procedure you outlined is precisely what I'm looking to do. I'm assuming that the "preserve current assignment" option for array slots and pool slots preserves the current state only for *new* drives that are already installed and configured in the array, leaving the data drive from the old server as an unassigned device, correct? (Which I would then assign as an additional data disk in the new array?)

Sorry if I'm being overly cautious/detailed here, but I'd rather not lose this data if possible. While I do have backups of it, it would be a pain to reconstitute. 

 

As for the old parity drive, yes, I would like to repurpose that as an additional data drive. I guess after adding it to the new box, it should also appear as an unassigned device like the data drive, except it will show as needing formatting. (Whereas the old data drive should *not* indicate that, right?) After all that, the parity drive will be updated to recognize the added drives.

 

If I've got all that correct, I'll take a deep breath and go for it. Thanks again!

[ChatNoir]

26 minutes ago, Terpinol said:

If I've got all that correct, I'll take a deep breath and go for it.

Looks like you got it.  

[Terpinol]

Okay, unfortunately I'm back. I followed the procedure outlined above, but it doesn't appear to have worked quite right, in my case at least.

 

I added two additional drives from my old array (one old parity drive, the other containing data). They showed up on the new server as unattached storage. Actually, *all* the drives, old and new, initially appeared as unattached drives, but I was able to add the original three (one parity, 2 data) back into the array without any problem. But when I attempted to add either of the two "old" server drives to the array, I got the error, "You may not add new disk(s) and also remove existing disk(s)." I rebooted the server, but the error persisted. Finally, I read on another forum post that the error was because I needed to "... let the parity sync finish before adding new disks (or doing a new config), you cant add new disks while parity is not green." So, I left the parity to sync overnight and it finished without errors. However, when I try to add my data disk to the array, I get a warning that "all data on this device will be overwritten when the array is started."

 

So, I'm back to square one. I can't seem to find a way to add the old data disk from my old array into this new array without losing its data, even though I did a New Config on it beforehand. 

 

Any advice on how to add the data disk, or do I have to resort to copying the data over? (If I have to do that, it's not the end of the world, just annoying and time-consuming, considering the data's already there.)

Thx.

[Terpinol]

citadelii-diagnostics-20211218-1255.zip

[trurl]

Sounds like you didn't really follow the procedure. At step 6 you were supposed to add the drives from the old server, before starting the array to rebuild parity.

 

 

You will have to do it again.

[trurl]

Just now, trurl said:

At step 6 you were supposed to add the drives from the old server

Perhaps a better verb than "add" would have been "assign". You need to assign the disks to new slots, not simply install them.

 

New Config, assign the disks as needed, rebuild parity.

[Terpinol]

Thanks for the further clarifications, trurl. It's clearer to me now what New Config does, and as a result, I was able to finally get the old disks added into the new array. And after another long parity rebuild, all seems to be well now. Thanks to you and ChatNoir for your patient help, it means a lot to a new guy - appreciate it.