I am expanding my array by changing for bigger drives.

Before that i precleared the drives to test them.

I have 2 6TB parity drives replaced with 16TB drives.

I was thinking that it would be nice if parity rebuild could end when the biggest of the disks has been read if the disk being rebuild has been precleared. I don't know if i'm clear.

In my case, older disks are slow, rebuilding has reached 6TB and there is 10TB more to go but nothing is read from other disks as they are smaller. I assume the rest of the parity sync is like zeroing the disk which has already been done by preclear.

4 hours ago, caplam said:

I assume the rest of the parity sync is like zeroing the disk which has already been done by preclear.

Yes and normal.

so it could spare time, if the disk has been precleared, to end parity sync.

Right now parity sync has been paused because of mover action and i had to manually resume. And yet parity disk being rebuilt is the only one disk being accessed by the array. 

2 hours ago, caplam said:

so it could spare time, if the disk has been precleared, to end parity sync.

Preclear is not a standard part of Unraid which is why I suspect that it is never checked for.   If you know that you are going to use a disk for parity then there is no real reason for pre-clearing it as the parity sync process writes to every sector on the drive anyway.

 

2 hours ago, caplam said:

Right now parity sync has been paused because of mover action and i had to manually resume. And yet parity disk being rebuilt is the only one disk being accessed by the array. 

if mover is running then it must be writing or reading array drives so resuming the parity sync will slow down mover.  If the pause is being done by the Parity Check Tuning plugin then if you do not want the pause to happen uncheck that option in the plugins settings.

 

3 hours ago, itimpi said:

Preclear is not a standard part of Unraid which is why I suspect that it is never checked for.   If you know that you are going to use a disk for parity then there is no real reason for pre-clearing it as the parity sync process writes to every sector on the drive anyway.

It makes sense. I only ran 1 pass preclear for testing. It's a brand new disk. And i had 3 other disks in preclearing process. All drivres are exos (3x16TB 1x8TB). These are getting really hot when running preclear mounted in the same das case.

 

3 hours ago, itimpi said:

if mover is running then it must be writing or reading array drives so resuming the parity sync will slow down mover.  If the pause is being done by the Parity Check Tuning plugin then if you do not want the pause to happen uncheck that option in the plugins settings.

 

I had the impression mover was stalled. There were no reading or writing on the array. As soon as i resumed there has been writing only on the parity disk being rebuit.