I Like Rockstor but it's reliance on BTRFS quotas is starting to become a real problem (Essentially BTRFS quotas absolutely annihilate performance, drop a load of snapshots with them on and the system is unsable for hours,turning them off causes Rockstor to break in the current versions)
Whilst I could easily(ish) go to a straight Centos/Debian install where's the fun in that (also I quite like the OMV gui)
So what I'm about to attempt is to mount the BTRFS Raid6 created by Rockstor on OMV.
Firstly though I'm building a 4.12 kernel for OMV before I let it anywhere near my disks (Lots of Raid5/6 fixes in the newer 4.xx kernels) already updated btrfs-tools.
Then we can see how much *fun* getting the array to mount is going to be.