I'm coming to the end of preclearing 3 8TB drives and just want to check that my next steps are ok.

 

1 Stop array and deselect old parity.

2 Select 1 8TB drive as parity and start array, rebuild parity, check parity.

3 Add a second 8TB as 2nd parity drive, rebuild parity, check parity.

 

If all that is ok, preclear old parity and add to array along with a 3rd 8TB drive.

 

I realise that while parity is rebuild it would not be wise to write the array but reading should be ok.

 

Kevin.

Do you already have a parity2? If not you might as well build them both at the same time.

And, as long as you trust that your old parity drive is still in good shape, no need to preclear it if you just add it as a data drive by setting a new config.

 

Actually, that would be the safest option IMHO, as you would be keeping the old parity intact while building your 2 new parity drives.

 

So, set a new config, assign 2 of your 8TB's as parity 1 and 2, your old parity drive and one of the 8TB's as data drives along with the rest of your existing data drives. Build parity, check parity, after that comes back clean you can format the old parity drive.

 

Up until the point you format the old parity drive, you could theoretically use it to rebuild another failed drive unless you write to the array. Like you said, reading should be fine, but be aware that some apps like to write metadata about the files they read.