12.04 fail to install grub2

[Drone4four]

At the end of the installation procedure of 64 bit Ubuntu 12.04 on a reformatted partition, I got a grub2 fatal error 10. I rebooted and the grub2 command prompt read, "error: unknown filesystem." How can it not know the file system? I chose btrfs. So I boot the live-USB and search around on Google and stumble upon boot-repair, which ostensibly seemed like a useful utility. I install the app and then run it. I click the recommended repair option. At the end of the process, it gave me this link to share for further troubleshooting purposes: http://paste.ubuntu.com/950561/
Upon rebooting my PC, all I get is the Windows loader. There is no trace of grub2. I write this forum thread from Windows 7.

What has gone wrong and how do I get 12.04 running? What other information could I provide?

[oldfred]

grub2's boot loader is in sdb. Have you tried booting from that. Not sure about btrfs file systems, but these says it should work.

http://askubuntu.com/questions/113318/can-12-04-be-installed-using-btrfs-only

But boot script does not look like it mounted your sda7. Is a driver missing with boot repair or your liveCD?

You also have Windows 7 in a logical partition. Do not ever delete your XP sda3 partition as the 7 only boots thru the XP partition. All of Windows 7 boot files are in the XP partition.

[Drone4four]

oldfred: You said something that I don't understand. You said:


But boot script does not look like it mounted your sda7. Is a driver missing with boot repair or your liveCD?


What do you mean by that? What does boot repair have anything to do with its drivers and my live-USB? Since when do boot loaders handle drivers? I thought the boot loader would load the kernel which would then load the drivers later. Could you please elaborate and clarify?


You also have Windows 7 in a logical partition. Do not ever delete your XP sda3 partition as the 7 only boots thru the XP partition. All of Windows 7 boot files are in the XP partition. It's good that you pointed that out. I'll keep that in mind.


grub2's boot loader is in sdb. Have you tried booting from that. Not sure about btrfs file systems, but these says it should work.

Using boot repair I will install grub2 on sdb. If that doesn't work, I will try reinstalling Ubuntu using a different filesystem, ext4. I will go ahead with this and report back here with the results.

[oldfred]

I was referring to a btrfs driver. I know nothing about it but it was unusual for script not to show anything about that partition. I notice that grub2 has a btrfs.mod that it should load to boot a btrfs partition like it loads ntfs for Windows. I thought whatever Ubuntu needs for btrfs was now part of system.

[Drone4four]

Well I think you were right, oldfred, because after reformatting the drive using ext4, Ubuntu installed w/o any grub2 fatal errors. When I rebooted for the first time, it still went directly to the Windows Loader. So I booted the live-USB and installed and ran boot-repair. That enabled grub2 to load at boot. I am writing this forum post from Ubuntu 12.04. Thanks, oldfred.