Crazy way to rebuild ZFS Pool?

TrueNAS General
1

Crazy idea here.

I have a 4 disk ZFS raidz1 pool. I would like to have a 4 disk ZFS raidz2 pool.

Is this a Crazy/Stupid way to do this?

  1. Remove one drive from the pool.
  2. Create a new one drive pool on that removed disk.
  3. Replicate the degraded 4/3 disk pool to the new one disk pool.
  4. Destroy the degraded 4/3 disk pool.
  5. Create a new 3 disk raidz2 pool.
  6. Re-Replicate the pool from the one drive pool to the new Raidz2 pool.
  7. Destroy the 1 disk pool.
  8. Expand the 3 disk raidz2 pool by adding the removed disk back.

I have 12TB drives and about 6TB of data that matters so there is plenty of space. I also have a backup server but I fear relying on it when I do not have to.

2

It’s better to find out now that your backup server is or isn’t working. You don’t mention what you have for a backup so I am guessing a single disk, no redundancy.
It would be simple to just verify the backup, destroy the current Raid-Z1 and create the Raid-Z2 pool with all 4 drives using the GUI. If you do it your way, you will have to use the command line to create the 3 wide Raid-Z2. Space reporting in the GUI will be a bit off if you use Raid-Z Expansion. The command line will be more accurate.

3

The backup isnt that bad. its an ancient hp with a i3-2130 processor truenas and a 3 disk raidz1 buti do see your point.

4

If the backup is up to date, a single replication will do it.
Your plan involves two replications, CLI wizardry to create a degraded raidz2 and then a resilver, so it’s a clear case of “Why make it simple when you can have it complicated?”.

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