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I'm trying to install ubuntu Server to a RAID5 array. I have three, 3Tb disks, each with a GPT partition table. I have set up my partitions as follows:

1. 512 Mb physical RAID volume
2. 3 Tb pysical RAID volume

1. 512 Mb physical RAID volume
2. 3 Tb physical RAID volume

1. 512 Mb physical RAID volume
2. 3 Tb physical RAID volume

The raid volumes are grouped into two md devices:

1. 1.5 Gb RAID5 (mount point:  swap)
2. 6.0 Tb RAID5 (mount point:  /)

Installation proceeds normally until it is time to install GRUB2. I get an error that reads:

Unable to install GRUB in /dev/sda
Executing `grub-install /dev/sda` failed.
This is a fatal error.

Why is this happening and what can I do to fix it?

share|improve this question
I would suggest try with another bootloader but i don't know if Ubuntu will let you choice – Felipe Morales Jan 16 '14 at 21:18
@Felipe.M - and what bootloaders would that be? It is more whether the bootloader will run Ubuntu, not whether Ubuntu will let it... You could use EasyBCD to modify a Dual-Booted Windows bootloader. blz - how are you implemeting this? Is this from a working system, or a Live Disk? And shouldn't the installer do this for you? If it boots, it works :-s – Wilf Jan 16 '14 at 22:20
@wilf, this is precisely my problem -- the installer should do this, but it fails with the error message I reported above. Again, for clarity, this is all taking place in the ubuntu-server text isntaller. – blz Jan 16 '14 at 22:47
up vote 1 down vote accepted

It seems that GPT-partitioned drives require a bios_boot partition when used in conjunction with BIOS. Here is a tutorial that worked for me.

Also note that one of the drives subtending the RAID array must have a /boot partition configured. Again, for clarity, you will need:

  1. A small (~1 MB) bios_boot partition
  2. A /boot partition

begin rant

Holy uninformative error message, GRUB! Good lord!

end rant

share|improve this answer
I don't know what this 'BRUB' is that you tried to install, but grub does give a bit more informative error message. – psusi Jan 17 '14 at 2:31
@psusi, I beg to differ. The grub error above is what I was presented with, verbatim (minus the typo). – blz Jan 17 '14 at 3:36
Yeah, really need <rant> tags... – Wilf Jan 17 '14 at 10:43
Did you not read the first part of my comment? You weren't installing grub.. or was that just a typo? There are a few goofy forks of grub out there that people use, I think another one was called BURG... at any rate, there should have been another line you cut off above that one saying something about gpt, and no bios_grub found... – psusi Jan 17 '14 at 14:43
@psusi, I did, hence the bit about the typo =) I was installing GRUB, but my stupid brain decided to type BRUB. – blz Jan 17 '14 at 21:04

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