Does FreeNAS 9.3x use ZFS to mirror disks?

[SumoX]

Hi All,
Does FreeNAS 9.3x use ZFS to mirror disks?

I'm just getting started (or restarted to be exact, I made my NAS about two years ago when AMD was on the recommend list)

Anyway having after updating myself it's clear I need ECC RAM. It's going to take my a couple of months to build a new NAS with recommend Spec's. So my plan until then is to use Mirroring with 6 x 2TB drives, not to be susceptible to ZFS file system with non ECC RAM.

But this will only work if mirroring in FreeNAS in 9.3 does not use the ZFS to mirror.
Thus my question?

 

[danb35]

FreeNAS 9.3 only uses ZFS. This is true whether your pool is striped, mirrored, RAIDZ, or some combination of those.

 

[SumoX]

Cheers...
So I suppose it won't make any difference if I mirror or RaidZ2?

 

[Robert Smith]

There is difference. Basically, z2 is safer, per usable space, while mirror is faster. And you need a minimum of 4 disks for z2.

Mirrors can be made safer by going triple or more, but the space waste is higher.

 

[danb35]

So I suppose it won't make any difference if I mirror or RaidZ2?

Not with respect to hardware requirements, no. @Robert Smith has set out the main differences from a user's perspective. You can set up an n-way mirror for pretty much any value of n, but you're using n-1 of those disks for redundancy rather than storing more data. If you want more redundancy, you could do RAIDZ3 rather than Z2, too. It's a multi-way trade-off among cost, capacity, performance, and redundancy.