Capacity upgrade solution...

[Gimpymoo]

Hello.

Currently have a Pool of 10 x 3TB HDD's.

I am in need of more capacity but my current case has no more room.

My understanding is I cannot just replace two 3TB drives with two 6TB drives as ZFS does not work like that, I would need to upgrade the whole pool in one go to gain more space, correct? However I cannot afford to do that all in one go.

So my options are to build a second TrueNAS box or buy an even larger case? Have I got it wrong?

Thanks for any help/guidance.

 

[ChrisRJ]

If you have the possibility to temporarily offload all of your data, you could change the pool configuration to something like 8 drives in RAIDZ2 and 2 drives in mirror. But in general your assessment is correct.

 

[sretalla]

My understanding is I cannot just replace two 3TB drives with two 6TB drives as ZFS does not work like that

If your 10 disks are in mirrors (5 VDEVs), then you can swap the disks in one of the mirrored pairs (VDEVs) to gain capacity in the pool (at the cost of pool IOPS capability).

If you're using RAIDZ (1, 2 or 3) then it's as @ChrisRJ said.