Setting up OMV

Hi there,
after some tries + errors getting basic OMV 1.9 + omvextras 1.7 to run, it´s up and fitting my notion

Specs: 1x 120 GB System on SSD (20GB "root" + 4 GB swap ) rest undefined (raw)
4x WD RED 3TB ext4 formated

I´ve been playing with some configurations for the datastorage:

- Raid 5 -- ok but i don´t like that the disks can´t spin down
- snapraid solo -- no "nice" pooling function
- snapraid + mhddfs -- a bit to slow
- snapraid + aufs -- ok

So after reading this forum and do some investigation finding overlayfs. I think this would fit my concept.
But overlayfs is until kernel 3.18 released at 7.12.2014 and in the changelog of this kernel "Removed aufs".

So what you think?
Setting up snapraid + aufs and maybe getting problems when OMV get´s to stock-kernel 3.18 or port to 3.18 and setting up snapriad + overlayfs.

Some hints and tips would be great.

Sorry for my bad english it´s not my nativ language.

Ok, thx for the answer.
I´ll give aufs a second chance and switch to overlayfs when OMV support it