Hi,

 

I currently have a system with 1x3TB parity drive, and several data drives, the largest of which (3TB) is starting to report regular errors so I'm looking to change this out before it fails.

 

However, I have only 2x 4TB drives to go in the system, so obviously I can't just add one as a data drive as it would be larger than the parity. I wanted to check that I had this correct as I've not had to swap anything out previously except a failed cache SSD.

 

Is the only option to me:

 

1 - add new drives into the system

2 - first assign as new parity drive to the new 4TB

3 - allow parity to rebuild

4 - when complete, unassign the failing 3TB drive and assign the second new 4TB in it's place

 

The reason I'm a little cautious is that I wonder if the increased load generated as a new parity drive is created could accelerate the failure of the dying 3TB, and that I could be left with only a partially built new parity drive, and a dead data drive.  I get regular error notifications if the drive is under load.

 

I could be totally wrong about this, but I've really had no issues in the two years my Unraid box has been set up so I may be misunderstanding the process.

 

Is the above the best way to go about the replacement?  Reading through some of the guides I'd found it does look like it?

 

If you don't mind using the old parity as replacement for the failing disk you can use the parity swap procedure, new parity will be copied from old parity, so no stress on data disks, when that is done rebuild will begin on the old parity disk.

 

After that, and if you want, you can use the other 4TB disk to upgrade that (or another) disk.

Thanks!  I thought that was what I should do but was just a bit wary... Fingers crossed it goes smoothly! 

Worked perfectly, thank you!