Cannot boot into LUbuntu after configuring RAID

Question

I am having some problems trying to get LUbuntu working with RAID 0. (I am using LUbuntu Alternate 64bit).

My Setup:

• /dev/sda 2.0TB Physical Disk;
• /dev/sdb 2.0TB Physical Disk;
• /dev/sdc 2.0TB Physical Disk;
• /dev/sdd 2.0TB Physical Disk;

I run the installer and opt for the manual partitioning. On each disk, I create a partition:

• 1.99TB "physical volume for RAID"

I then create a software RAID 0 from each of the /dev/sd*1 partitions. This RAID partition is then set to Ext4, and mount point of "/".

Then on each disk I create another partition:

• 2GB "physical volume for RAID"

I then create a software RAID 0 from each of the /dev/sd*2 partitions. This RAID partition is then set to "swap" (so 8GB swap for 8GB RAM).

I then create a 1GB Ext4 partition on /dev/sda, and set the mount point of "/boot". (This is partition /dev/sda3).

Once done, I write the partitions to disk.

When I get to the GRUB install screen, I configure it to install to /dev/sda3 and everything seems successful, but on reboot it cannot find the operating system.

Am I doing this all wrong, or is there something I am missing?

Thanks

Answer 1

1. You should also make /boot a mdadm RAID-1, with 1GB partitions on each of the 4 drives (/dev/sd?3), so that /boot is still available even if /dev/sda or /dev/sda3 dies.

2. The BIOS does not look for the boot-loader (grub) in a partition like /dev/sda3. It looks for it at the start of the boot drive. In other words, you should grub-install to the disk device (/dev/sda), not a partition device (/dev/sda3). With a RAID setup like this, you should grub-install to ALL of the disk devices, so that they all have the grub boot-loader in the MBR. If a drive dies, your system will still boot.