.... during a drive expansion ( i've removed a 14TB drive and am replacing with an 18TB) there is a problem? I still have the original 14TB drive. Is it simply a matter of switching it back in and restarting? Should the drive expansion be running in maintenance mode to avoid any detrimental activity should the expansion go belly up? Jsut sitting here watching it slowly restore over some 2.5 days!!

So you’re rebuilding parity and you’re wondering if you put the old disk back in if parity would be valid again? If that’s what you’re asking then the answer is no. 
 

if you’re asking if the data is still on the old disk then the answer is yes the old data that was on the disk is still there.

 

Thanks. so, data is intact on smaller, outgoing disk as to be expected. but if you just wanted to put it, and the contents, back into the system then how do you get the data back in sync? wont reinserting the disk just prompt to overwrite?

It won't let you replace the 18 with the 14 without doing New Config and rebuilding parity.

6 hours ago, trurl said:

It won't let you replace the 18 with the 14 without doing New Config and rebuilding parity.

So, how do i get the original 14TB drives data back onto the array without losing it?

 

Is it  a case of mounting it externally and purchasing another drive for the array which then takes a move of the data, if so that seems a very long winded fix?

 

 

21 hours ago, MowMdown said:

So you’re rebuilding parity and you’re wondering if you put the old disk back in if parity would be valid again? If that’s what you’re asking then the answer is no. 
 

if you’re asking if the data is still on the old disk then the answer is yes the old data that was on the disk is still there.

 

I'm expanding the system by adding a larger drive to replace a smaller one having ran a parity check to ensure all data is ok. If the expansion process fails and the disk is

being emulated how do i proceed. The original data disk is at this stage outside of the array but fully functional.

You would physically swap out the drive you were using as a replacement and reinstall the original drive (with your data).

The array won't start, as there is now an assignment mismatch.

You correct this by using the New Config utility in the Tools tab - https://docs.unraid.net/unraid-os/manual/tools/#new-config

Once you set the configuration (with the drive in the correct slot) you will then be able to start the array, and your server will then rebuild parity.

If you're expanding the array by swapping a smaller disk for a larger disk, assuming the larger disk is no larger than your parity disk(s), you would simply rebuild the data onto the new disk, this would keep parity valid during the process. If this new disk fails, you should be able to do the steps again but adding the old disk back in and you should be up and running again. The most important step will be to ensuring you check the box that says "parity already valid" otherwise parity info gets wiped out.

 

All of that is detailed here: https://docs.unraid.net/unraid-os/manual/storage-management/#replacing-a-disk-to-increase-capacity

 

But I will say this, do not proceed with doing the reverse without consulting the forums first in case some other steps need to occur.

Edited April 1, 20251 yr by MowMdown