On Thu, Mar 24, 2016 at 11:52:05AM +0100, Christoph Pleger wrote: > Hello, > > I am trying to use an "LSI Megaraid Software RAID" with mdadm, but I have > not been successful so far. When I configure a RAID 1 in the BIOS > Setup-Utility and boot from network with an NFSROOT, a ddf container > device is detected as /dev/md127 and a raid device as /dev/md126, but when > I reboot, the previously created RAID configuration has been destroyed, > that is, when I start the BIOS-RAID-Utility again, it does not 'remember' > the configuration it created earlier. > > As a solution of the above problem, I already tried to create an mdadm > RAID 1 without BIOS support, that is, I deactivated the RAID feature in > BIOS-Setup and after booting with NFSROOT, used 'mdadm --create ...', but > I did not manage to make that RAID bootable. > > So, how can I setup a RAID 1 over two whole disks with mdadm?
You can either use the LSI's built-in RAID system or mdadm but not both. Don't use the fakeraid. If you actually have a decent LSI card (2002 or 3003 chipset) you could use the real RAID that is provided there, instead. In that case, RAID will show up as /dev/sda. Configure the LSI to present individual disks and then use mdadm the normal way: partition the disks into two sets, a small /boot partition and a large /. (Or three partitions per disk: /boot, / and /home.) Create mdadm pairs for each of sda1,sdb1 sda2,sdb2 sda3,sdb3 ... and set /dev/md0, for /boot, as bootable. The Debian installer can handle all of this easily. -dsr-
