Shrinking Array - 2 Drives at once?

[kavo]

Forgive me if I have missed this being covered but I have done some searching and can't really see anything that fits what I want to do.

 

I have just been through the process of upgrading my parity to 10tb drive and an array drive to 10tb. I want to remove 2x2tb drives from the array. I have copied all data off these 2x2tb drives. Is it possible to remove 2 drives at once or following the guide for The "Clear Drive Then Remove Drive" Method at Unraid Wiki - Shrink Array do I have to remove 1 then rebuild parity then remove the other then rebuild again?

 

Im asking because at this stage my server has been unuseable for about 4 days just trying to upgrade these drives in terms of parity rebuilds, moving files etc

[JonathanM]

You will either have to write all zeroes to the 2 drives you wish to remove, or rebuild parity. You can set a new config and rebuild parity after removing both drives at once, you don't have to do them individually.

 

Not sure what constitutes unusable to you, the array files can still be read while parity is building, albeit slower than normal.

 

Writing all zeroes to the two drives will keep parity busy much longer than simply rebuilding it once.

[kavo]

Thanks ok maybe I am understanding the method on the wiki https://wiki.unraid.net/Shrink_array but what I have done so far:

1. Replace parity drive to 10tb
2. Rebuild parity
3. Replace array drive 6 with 10tb
4. Rebuild drive
5. Move all files from Drive 5 to drive 6
6. Move all files from Drive 4 to Drive 6 - This is about to finish

So my next move will be to stop the array. go to new config, unassign both drives 4 and 5 (at the same time?). then rebuild parity?

 

I say unusable as I disabled all downloading, plex etc during the parity rebuild and copy to try and speed things up. 10tb parity rebuilds arent fun

[JonathanM]

10 hours ago, kavo said:

So my next move will be to stop the array. go to new config, unassign both drives 4 and 5 (at the same time?). then rebuild parity?

Yep. Your wording leads me to believe you haven't used the new config tool before, so to be clear, you go to new config, set preserve all, then go back to the main GUI page and select none for the two drive slots you are removing. If you don't preserve all, you will need to refer back to a saved list of your current drive assignments so you don't accidentally put the wrong drive in a parity slot.

 

Do NOT select parity is already valid unless you go through the very long process of dd'ing zeroes to the drives to be removed.

[kavo]

22 minutes ago, jonathanm said:

Yep. Your wording leads me to believe you haven't used the new config tool before, so to be clear, you go to new config, set preserve all, then go back to the main GUI page and select none for the two drive slots you are removing. If you don't preserve all, you will need to refer back to a saved list of your current drive assignments so you don't accidentally put the wrong drive in a parity slot.

No i haven’t used it. I’ve only

ever expanded the array or replaced drives. I’m assuming all your advice above is when the array is stopped?

 

will it matter if I am leaving disk 6 but removing disk 4/5?

[JonathanM]

Yes, array stopped. If you want to reorder your data slots, now's the time to do it. As long as you don't assign a drive with data to the parity slots(s), you can put the drives in any slot you wish.

[kavo]

10 hours ago, jonathanm said:

Yes, array stopped. If you want to reorder your data slots, now's the time to do it. As long as you don't assign a drive with data to the parity slots(s), you can put the drives in any slot you wish.

Thanks. Do I need to unassign the two disks im removing from shares? because I am removing disk 4 and 5, disk 6 will obviously become disk 4 in the new state. So I don't want to screw this up

[JonathanM]

3 minutes ago, kavo said:

Do I need to unassign the two disks im removing from shares?

Depends. You need to reevaluate your includes and excludes depending on which disk # end up where and what shares you want to be on them. Never use both include and exclude, only one or the other.

 

[kavo]

I currently have no shares with disk 4 or 5 marked for inclusion/exclusion specifically