How to replace RAID1 pool with larger disks

TrueNAS General
1

I have RAID1 mirror set up with 2x2TB drives. It is getting close to full. I am looking to replace those 2TB drives with brand new 8TB ones.

I don’t want to recreate the data pool because I have apps and many other things set up to depend on the dataset.

Can someone please outline the steps I can go about replacing those 2TB drives with the new 8TB drives? Thanks.

2

Replace the one disk, then replace the other. The manual (link at the top of the page) describes how to replace a disk…

3

I just replaced a failing disk recently. It was a pool of 1.5TB size with 2 mirrored 1.5TB disks. I replaced the failing 1.5TB disk with a 2TB disk, but I don’t recall there is an option to increase the pool capacity. The pool is still 1.5TB capacity after the replacement.

Maybe I need to replace the 2nd disk in the pool, then there will be an option during the replacement to increase the pool capacity?

4

Yes, you do; a mirror is limited by the size of its smallest member device.

There shouldn’t be any option; it should happen automatically.

5

So when replacing disks in the pool, the final size of the pool is dynamically determined by the smallest capacity in the array? Interesting.

6

The final size of the vdev is determined by the smallest capacity in the vdev.

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