I've been trying to install Ubuntu with software RAID on my server and there is obviously something that I don't understand about the process.

This is the guide that I followed: https://help.ubuntu.com/11.04/serverguide/advanced-installation.html

I have two identical 1 TB disks in my server. I went through the initial install process and manually set up my partitions. On each disk I set up:

  • (1) 100 MB partition for EFI boot (I didn't originally have this but added it based on a forum post I found after my original install failed to boot, I ended up with EFIboot since that was what the 'guided partitioning' decided to do)
  • (1) 970 MB partition for /
  • (1) 30 MB partition for swap

I then created new RAID 1 disks combining the two partitions, one from each disk, such that each partition is mirrored. I then configured their usage as stated above. After saving the configuration I said yes to boot in a degraded state.

The rest of the setup went normally, no errors of any kind. I saw GRUB being installed and again no errors. However, after rebooting the server I get the dreaded 'Insert boot media' and nothing happens.

I loaded up the recovery disk and the mdadm configuration looks correct.

  • md0 is my EFIBoot partition
  • md1 is my \ partition using ext4
  • md2 is my swap partition

Running file -s /dev/md0 doesn't indicate that GRUB is there and so I attempted to reinstall GRUB using the recovery disk. I selected the md0 disk and it appeared to install just fine.

Running file -s /dev/md1 shows the error needs journal recovery, I'm not sure if that's related or not or how to fix that.

Rebooting gives me the same problem, no boot media found. I've searched around the internet but can't figure out what to do next or more importantly how to troubleshoot what exactly is going wrong.


  • 1
    Are you booting using EFI or BIOS MBR?
    – mgorven
    Commented Jun 16, 2012 at 5:37
  • I started over and switched to BIOS MBR and things seem to be working.
    – Bill
    Commented Jun 19, 2012 at 2:23

1 Answer 1


I think that your problem is putting the EFIboot partition on a RAID device.

I just finished sorting out the same issue, and the procedure that worked for me is the following:
- use the "manual" partitioning option during install, as you did
- for each of your disks, delete the partiton table, and then "automatically partition" the free space (let the installer give you a hand!)
- there might be some 1 MB space left at the beginning and at the end of the automatically created partitioning table; I do not know the reason, nor if it is required, but it is not an issue and it works for me
- now modifiy the automatically generated partition table: use the ext4 and swap partition as "phisical RAID devices"
- leave the EFIboot partition untouched. When you "automatically partition" the second drive, you will notice that the Ubuntu installer deletes the EFIboot partition on the first drive: there should be only one in total. The previous one will be marked as vfat32, and you can leave it like this.
- now create the RAID devices as you already did (md1 and md2 in your text; you will NOT need md0)
- continue installation as usual and reboot

Two more advices:
1) if it does not work the first time, try deleting the partitions a few times with e.g. gparted and retry; I found that sometime the disk "remembers" the partitions somehow
2) after successful installation, you can use dd and mirror the EFIboot partition on the second drive: this will serve as a fallback if the first drive fails

Good luck!

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .