Cannot boot from software RAID with 2TB disks

[Christopher Chan]

On Wednesday, May 12, 2010 03:35 PM, Matthias Brennwald wrote:
> Dear all
>
> I just installed Ubuntu 10.04 to a RAID-5 array (md/software array with 4 x 2TB plus 1 x 2TB spare disk, so 6TB in total). I followed the instructions here:
> https://help.ubuntu.com/community/Installation/SoftwareRAID

You missed this part on that page:


Warning: the /boot filesystem cannot use any softRAID level other than 1 
with the stock Ubuntu bootloader. If you want to use some other RAID 
level for most things, you'll need to create separate partitions and 
make a RAID1 device for /boot.

>
> However, the installer could not install GRUB. I finished the installation without installing GRUB and then rebooted from the installer CD (alternate) and chose to "repair a broken system" and then ran a shell with /dev/md1 as my root system. Then, I did this (again, according to the documentation mentioned above):
>
> grub-install /dev/sda    --->  this worked with not errors
> grub-install /dev/sdb    --->  this did not work, there were two messages from grub-setup:
>
> 		warn: This GPT partition label has no BIOS Boot Partition; embedding won't be possible!.
> 		error: embedding is not possible, but this is required when the root device is on a RAID array or LVM volume.
>
>
> I have no clue what this is all about, so i entered the above warning to Google and found the following:
> https://bugs.launchpad.net/ubuntu/+source/partman-base/+bug/506670

I have not looked at that link but I am pretty sure it has nothing to do 
with your problem. No operating system supports installing to a raid5 
unless it is a hardware one and therefore not handled by the operating 
system and even if it is hardware raid5 it may or may not work.


>
> What are my options? I'd appreciate any hints and help on how I can make this install work.

Only one. Destroy and redo it. 2 disks mirrored for system and the other 
three a raid5 to be used however you like.