Multiple Hard Drives with Different Capacities - Optimal Setup

[veblen]

Hello all,

I've decided to build a NAS with old hardware and stumbled on this excellent community. I've read cyberjock's primer on vdev/zpool and think I have a pretty good idea of what to do. I've also searched for similar topics and came across good advice.

Nonetheless, just to be sure, I'd like to check here before I jump into the process. :)

Core setup: i3 530/H55/8GB RAM
Storage setup: 3x640GB and 2x1TB

1. Given five drives of different sizes, RAID-Z2 is out of the question unless I sacrifice space on the 1TB drives - is that right? That is, I can have 3x640GB + 1x1TB in RAID-Z2 but will lose space on the 1TB.

2. This leaves me with either:
a. 3x640GB in RAID-Z1 (one for redundancy)
b. Buy another 1TB and have 3x1TB in RAID-Z1 as well

Option 2a will leave me with approx. 1.28TB before formatting, and I'll have to think about what to do with the 2x1TB drives.

Option 2b will leave me with approx. 1.28TB before formatting from the first zpool, and 2TB before formatting from the second zpool for a total of 3.28TB, again before formatting.

Have I understood this correctly? And are these my optimal options?

Thanks for any help!

 

[ProtoSD]

I think you have a 3rd option which will give you ~1.6, but your option 2b sounds good as well.

Take the 3 640's and make a Raiz-Z1 in one pool, then make a mirror with the 2x 1TB's in another pool.