Need help with configuring drives for redundancy

[udit]

I have an old AMD Phenom x6 PC and figured I'd tinker around with it. My disks are as follows

3x1 TB (currently in zraid)
1x2TB
1x8TB ( newly acquired and shucked from a WD black)

I don't need more than 5-6TB of storage atm.
I'm thinking there is a way to mirror the 3 1TBs and the 2TB on the 8TB drive and used the unused space as additional storage. But i'm not exactly sure how to go about doing it or if that is even the best way to do it. I'm already re-purposing old drives, so buying new ones is out of the question.
What would you guys recommend?

 

[jim.bond.9862]

IMHO, get a second 8tb. Add it as a mirroed zpool.
Move all from 1tb pool onto this new 8tb pool.
Sell your 1tb and 2 tb disks and enjoy.
Later just add a second pair of 8tb to expand the pool.

 

[udit]

Yes I've thought of that but I can't really buy another 8TB disk lol. I want to make do with what I have currently. Adding another pair is much later in the future.
Just need a way to mirror these onto say different partitions on the 8TB