I have a RocketRAID 2720 card and before I decided to use OMV I did some research to see if this card was supported. I found, much to my surprise, that this card, as well as most of the Highpoint cards, is supported by using the Backports kernel as mentioned in this thread (and others). Well this is only somewhat true, as I found that when I installed the backports kernel my 6x2TB RAID5 array showed up as 6 individual 2TB disks, as opposed to the single 10TB RAID5 array that I created. The purpose of this tutorial is to get the proper driver from Highpoint installed so that the array you have configured shows up in OMV.
1) Start by installing the Backports kernel (note: kernel version number may be different)
echo "deb http://backports.debian.org/debian-backports squeeze-backports main non-free" >> /etc/apt/sources.list
apt-get update
apt-cache search linux-image-3
apt-get -t squeeze-backports install linux-image-3.2.0-0.bpo.4-amd64 firmware-linux-free
2) Install the kernel headers (note: kernel version number may be different)
3) Download the drivers from Highpoint's site (note: you will have to go to Highpoint's site and get the correct URL)
wget “http://www.highpoint-tech.com/BIOS_Driver/rr272x_1x/Linux/RR272x_1x-Linux-Src-v1.4-120424-1752.tar.gz”
4) Extract the files
5) Install the driver
cd product/rr272x/linux
make
cp ./.build/rr272x_1x.ko /lib/modules/$(uname -r)/kernel/drivers/scsi
depmod -a
6) Now we need to Blacklist the mvsas module as it gets loaded before this driver we just compiled
7) Delete and recreate initramfs
Reboot and enjoy!
These steps are written out specifically for the RocketRAID2720 card. If you have a different card, you will need to change some value accordingly. I am still working on getting the WebGUI to work on this as well. I have installed and configured everything but still get a "Driver is not loaded" error. If anyone has resolved this, I would love to hear from them, otherwise I will update this tutorial if/when I figure it out. Thanks