Hello. I am sorry if my question already have been answered earlier in this forum, but I have done some searches and havent found a specific post that matches.

I have a small Unraid-system just to use the Docker-functionality and have reused two 4TB drives and added two SSD 512GB as cache. So, my setup is one 4TB parity and one 4TB datadisk plus mirrored cache-disks och 512GB. The plan was ofcause to add more disks but that never happened since I dont need much space.

Now the data-disk hade gone down permanently and I am going to change the parity to a new 8TB disk and the datadisk to a 6TB. What is the best way of doing this since right now I am running only from the parity disk.

Shall I add the 8TB first to the 2nd parity slot and let it sync up and then add the 6TB datadisk? Im asking just because I am on a thin line here with only one parity disk working at the moment. There is no room for error. :)

I hope I will get this sorted out before I loose the parity disk too. ;) I am running Unraid 6.12.13.

/Fredrik

Edited August 15, 2025Aug 15 by Dernebo

What exactly is wrong with the data disk?

Attach Diagnostics to your NEXT post in this thread.

The Data DIsk is marked as "Disabled". It is reused old disks that are going to be replaced anyway with new Toshiba NAS N300 drives. I havent even concidered if the datadisk is possible to get working again since it is such an old disk.

I attached the diagnostics anyway if that helps.

iplast-diagnostics-20250815-1029.zip

Looks like disk1 dropped offline, so there's no SMART report, check/replace its cables and post new diags after array start.

On 8/15/2025 at 11:22 AM, JorgeB said:

Looks like disk1 dropped offline, so there's no SMART report, check/replace its cables and post new diags after array start.

Data disk is dead and need to be replaced. So I want to replace both disks. 8TB for the parity disk and 6TB for the data-disk. In what order shall I do the replacement?

You can do a parity swap, or since there's only one data disk, parity will be a mirror, do a new config, use that as disk one, resync new parity, then upgrade disk1.

1 hour ago, JorgeB said:

You can do a parity swap, or since there's only one data disk, parity will be a mirror, do a new config, use that as disk one, resync new parity, then upgrade disk1.

Seems to work perfectly. I didnt know that the parity disk was able to just change place with the datadisk without problem.

I did as you said, new config, assigned cache-disks, assigned old parity as datadisk, and the new 8TB disk as parity. Everything booted up and so far I havent noticed any glitches at all. Parity is rebuilding, and swapping the datadisk tomorrow to the new 6TB disk shouldnt be a problem.

Thankyou very much for your help.

2 hours ago, Dernebo said:

perfectly. I didnt know that the parity disk was able to just change place with the datadisk without problem

This is a special case where you have 1 data disk and parity1. No other combination allows this.