Ask Ubuntu is a question and answer site for Ubuntu users and developers. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I am attempting to setup software raid with my 3Tb harddrives.

I have partitioned each with GPT and 3 sections. (1 Bios, 1 Ext4 1 swap). The swap and ext4 are joined with raid. Installer goes fine, grub installs fine. When i get to boot i get error mduuid/ random hash not found.

This has happened three times now. I am in grub rescue.

Listing my drives, it shows each partition of each drive. I am lost on how to fix this.

share|improve this question
Edit your question to show us the output of sudo parted -l. – guntbert Sep 6 '13 at 16:00


Check to make sure your bios RAID is disabled. I installed linux raid and was unaware that my bios supported raid. Thus it was conflicting. I happen to catch it on long boot when i hit the wrong key to boot from usb

share|improve this answer

I see you have one bios partition, this indicates that your MBR is wrong. Grub has it's own type of MBR and does not need a bios partition.

Did you start with clean disks with no partition table on it or did you reuse the disks. This can be the reason why your system won't boot. Guess how I know.

First clean your disks with:

dd if=/dev/zero of=/dev/yourdev bs=512 count=1

replace yourdev with the device name of your disks

Then install Ubuntu again. It will then install new gpt partition tables. You only need a swap and a boot partition in raid ofcourse.

Don't forget to adjust your uefi settings in the bios.

Success !

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.