Looking for some opinions on how to partition my pools

[Hoowahman]

I'm putting together a new FreeNAS box soon and have the following:

13x4TB and 5x3TB with a case that can accept 15 drives and an existing pc that can accept 2.

I'd like to keep 1 harddrive each for a spare when one of the drives fails but I'd buy another one if the configuration makes sense. I've come up with 2 scenarios:

NAS: pool 1: 1 vdev of raidz2 consisting of 10x4TB drives = 32TB of usable space
NAS: pool 2: 1 vdev of raidz2 consisting of 4x3TB drives = 6TB of usable space
PC: 2x4TB = 8TB of usable space

Total: 38TB (redundant) + 8 TB = ~46TB

or

NAS: pool 1: 1vdev of raidz2 consisting of 6x4TB drives = 16 TB of usable space
NAS: pool 2: 1vdev of raidz2 consisting of 6x4TB drives = 16 TB of usable space
NAS: pool 3: 1vdev of mirror consisting of 2x3TB = 3TB (Jails + lesser important data)
PC: 2x3TB = 6 TB of usable space

Total: 35TB (redundant) + 6TB = ~41TB

What would you do with these drives especially for expansion in the future? PROS and CONS with each setup? Maybe I should upgrade to a bigger case and add a few more drives to get a better setup?

Thanks for any input!

 

[danb35]

Why are you looking at multiple pools at all? Whichever configuration you settle on for your vdevs (and the obvious pros and cons of capacity vs. redundancy), why not combine all the vdevs into a single pool?

 

[Hoowahman]

That's a good point. My reasoning there is that if one of the vdevs goes kaput I won't lose all my data. Also leaves some flexibility to move data from one pool to the other if I need to rework any of the vdevs in the future. I guess what I'm hoping for is flexibility in the future. Does that make sense?