Linux RAID Failed on Boot

After upgrading from Ubuntu 10.04 to 10.10 I noticed that my machine refused to startup on most occasions. After a few reboots it eventually decided to startup. I am running a raid0 setup which includes the boot partition.

I got an error stating that "one or more raid devices were degraded".

The solution turned out to be a simple one. It turned out that one of the HDDs in the raid array took a longer time to spin up than the others. This difference only became apparent in Ubutun 10.10.

The fix is to add a rootdelay parameter to your /etc/default/grub file and update grub.

Edit your /etc/default/grub file and update the following line to include a rootdelay:

GRUB_CMDLINE_LINUX_DEFAULT="rootdelay=90" 

You might need to increase your root delay if it still occurs after the above fix.

Update grub with

sudo update-grub

and you should be all good! :)