@roberto0610 I can chip in on:
Could it be that you have yet to select an update channel as per @Flox’s suggestion:
But the nub of your issue here is that the drive you are trying to install, i.e. designed for CentOS 7.6, will mostly likely assume a default kernel: which is where drivers live. But as the default kernel in CenOS and more specifically it’s btrfs subsystems, are way too old for practical btrfs use, we have had to ship our iso installs with a far newer kernel 4.10 and associated btrfs-progs. And then in turn have, via the testing and stable repos, again updated this to 4.12.
So the hope is that if you select an update channel you will then be offered the 4.12 kernel and that this in turn may cover your drive needs but if it doesn’t then you are in a tricky situation as we can’t feasably recommend the default CentOS kernel and btrfs progs yet you may be in a position where your currently required driver is only available for set kernels. Do they offer a driver that can be compiled against a given kernel version? If so then you could try that option as it will then be able to compile against the given Rockstor kernel.
Yes our iso is now quite old, hence the many updates. We are well on the way to migrating our offerings over to being based on openSUSE Leap15.1 and potentially Tumbleweed soon there after. But this is as yet not ready (but very much on the way). There is a very low likelyhood we will be releasing a new iso until that transition is complete and we have feature/function parity with our current CentOS offering; or near enough anyway.
Hope that helps.