Might be related to your RAID configuration – better check it with the support team. Yes volume level backup is supported for Bare Metal Restore.
do i need to create recovery media for each of my physical server to recover it from it's own recovery media or i just can use one recovery media to recover any server?
It's recommended to have the recovery media created under the same machine you are going to restore due the difference in hardware configuration and operating systems. You may have one recovery media for all your Windows 2008R2 server installations but then you should have all the drivers close to this recovery disk.