[ubuntu] 8.04 cleared the MBR partition table

[billbear]

I was quad booting leopard/vista/ubuntu/xp on my macbook. Last month I replaced the internal HD with a larger one, and installed leopard/vista/xp, and left some unallocated space for ubuntu hardy. I installed 8.04 last night, and found vista/xp/ubuntu unable to boot. It erased the MBR table!
Apple uses a hybrid GPT/MBR partition table for multi-booting with 'legacy' OSes. Ubuntu understands GPT but grub doesn't. When creating new partitions (beyond the first four) on a hybrid GPT/MBR disk, gusty updates the GPT table and leaves the MBR table untouched, but hardy updates the GPT table and erases the MBR table, thus makes xp/vista/ubuntu unbootable (because grub needs MBR)
Fortunately i have saved the MBR table information before (run fdisk /dev/rdisk0)
I then opened a terminal in leopard and ran the command sudo fdisk -e /dev/rdisk0, rebuilt the MBR table manually. After that all my OSes came back.

[cyberdork33]

Originally Posted by billbear I was quad booting leopard/vista/ubuntu/xp on my macbook. Last month I replaced the internal HD with a larger one, and installed leopard/vista/xp, and left some unallocated space for ubuntu hardy. I installed 8.04 last night, and found vista/xp/ubuntu unable to boot. It erased the MBR table! Apple uses a hybrid GPT/MBR partition table for multi-booting with 'legacy' OSes. Ubuntu understands GPT but grub doesn't. When creating new partitions (beyond the first four) on a hybrid GPT/MBR disk, gusty updates the GPT table and leaves the MBR table untouched, but hardy updates the GPT table and erases the MBR table, thus makes xp/vista/ubuntu unbootable (because grub needs MBR) Fortunately i have saved the MBR table information before (run fdisk /dev/rdisk0) I then opened a terminal in leopard and ran the command sudo fdisk -e /dev/rdisk0, rebuilt the MBR table manually. After that all my OSes came back.

Yea, this is confirmed by several people. Even dual boots don't work unless you sync with rEFIt first. Can you file a bug? This only happened very recently (RC or Final).

[ey1416]

I was dual booting windows and Ubuntu, then upgraded from Gutsy to hardy. Now my windows partition doesn't show up, which sounds similar to your problem. Is there any way for me to fix this?

[cyberdork33]

I filed a bug report. Please add info.
https://bugs.edge.launchpad.net/ubun...ty/+bug/222126

Originally Posted by ey1416 I was dual booting windows and Ubuntu, then upgraded from Gutsy to hardy. Now my windows partition doesn't show up, which sounds similar to your problem. Is there any way for me to fix this?

Are you on a mac?

either way, you can check what the MBR table looks like with fdisk

[slayer^_^]

i confirm this bug, my partitions went out of the windows after i installed hardy.

moreover i got error 17 : can't mount partition after i installed and i had to edit manually the grub config file changing my hd from (0,0) to (1,0).


DAMN !!!

[michaels]

synchronizing GPT and MBR is dangerous in some cases. The much better way is trying to handle and the stuff by yourself, which means installing grub on specific partition, not mbr. Besides, you have to always remember that grub can only be installed on first four partitions on your hard drive.

Good luck! Buddy!