Upgrading my raidz2 pool

OpenZFS
1

Hey everyone :slight_smile: I was hoping someone would help me understand some basics around maintaining a raidz2 pool.

I have a raidz2 pool of 5 8TB drives on my TrueNAS Core (FreeBSD) system – although what the operating system ZFS pool is running on probably doesn’t really matter. I’m getting a bit low on space here. On to of that one of the disks died on me so I started thinking on upgrading my pool altogether. Please, tell me if my understanding and, therefore, plan makes sense. :slight_smile:

I’d like to replace all the disks one-by-one (starting with the faulty one), but with 18TB drives. As I understand, during the replace process (while still having the mix of 8TB and 18TB drives) the capacity of my pool will remain 24TB. But after I replace the last disk (all 5 disks will be 18TB at that point) my pool automatically will grow in capacity to 54TB.

Is my understanding correct?

2

Yes, you have understood correctly how the pool auto expansion works (it is enabled by default iirc). Be prepared for extremely long resilver time with a raidz configuration with such large disks though…

3

You’ve got it figured right. If you can manage it, you may save some time by creating the new, larger pool and moving the data with zfs send/recv. Then you could export the old pool and import the new one with the original name.

4

Awesome, thank you so much for confirming. :slight_smile:

I’ll have to take my time and patiently wait each time for the resilver to finish – I don’t have any other machine to create the new pool. That’s fine, though :slight_smile: