reduce disks from 4 to 2 - best way

[kappclark]

I have a pool of 4 x 2TB disks, and was wondering if there is an easy way to 'rebuild' the truenas box so it is a pool of only 2 disks. Was thinking I wld need to create a new server, create pool of mirrored disks, then restore data ... wondering if this can be done in-place ...

The current setup is a raid 10 array (pool of 2 mirror vdevs) ... would like to reduce this to a pool of 1 mirrored vdev

 

[danb35]

In TrueNAS 12, yes, it's possible, if the pool is healthy and there's enough space on the remaining disks for the data on the disks to be removed. See:

Pool Screens

Describes the fields on the Storage Pools screen on TrueNAS CORE.

www.truenas.com

 

[kappclark]

Very helpful ... so I did some looking and it seems the pool is over 2T, so I have some housekeeping to do if I want to go through with this ...
so, if I understand the pool screens, I can simply remove the 2 disks of the other mirror leaving a single mirror...

also - you say possible in 12 -- I just did the 13 update ... problem ?

 

[danb35]

also - you say possible in 12 -- I just did the 13 update ... problem ?

I don't think so; the problem would be if you were using 11 or earlier. But I haven't used 13 yet so can't confirm.

And what you'd want to do is remove the entire second mirrored vdev in one go, not one disk at a time.

But yes, you have quite a bit to remove if you want the remaining data to fit comfortably on a pool of 2x 2 TB disks mirrored--it should be no more than about 1.5 TiB. Or consider buying a pair of 4 TB disks, replacing the disks of the pair you're going to keep one by one, then removing the second pair.

 

[kappclark]

Thinking, once data is reduced down to maybe 1.7T, I can remove the 2nd mirror from the pool ( ada2 and ada3 )... is that all there is to it ??

 

[kappclark]

OK - looking for 4 T disks !

 

[danb35]

That's all there is to it--but you're pool's going to be very full. Again, I'd shoot for a max of 1.5 TiB. Or put some larger disks into the pool, and then it's all good.