Skip preclear when adding former data disk?

[mr.sparkle]

I had a disk red ball on a bad sata cable, added a new disk and rebuilt fine. Now I'd like to add the first disk back and expand the array.

 

But when stopping the array and selecting the original disk to add, I'm only given the option to clear the disk. Is this a misnomer? It was precleared a while ago and smart tests still show everything is fine.

 

When I press the clear button, will it skip that part and just start formatting the disk and make the array available shortly? Or do I really have to preclear it again?

[RobJ]

To be added to an unRAID array AND keep parity valid, the disk MUST contain nothing but zeroes.  If you are sure the disk is fine, you can add it, but it HAS to be cleared first, either now by unRAID (which will keep the array offline for the duration) or by you with a Preclear.  You don't need the Preclear testing (if you are sure the disk is fine), so you can turn off the pre and post reading, but you do need the zeroing.  Preclear then adds a special signature at the front of the drive that unRAID will recognize, and trust that it really is all zeroed already.

[mr.sparkle]

Ah right, needs to be zeroed first (it's been a while).

 

So just preclear with the "-n" option to skip pre and post read?

[RobJ]

So just preclear with the "-n" option to skip pre and post read?

Correct.

[mr.sparkle]

And we're off! Thanks for your promptness, RobJ.