Quote Originally Posted by stillingen View Post
I've ended up with not being able to read /dev/sda after clearing the MBR. I've tried running from Ubuntu LiveCD. Is there a way to restore my MBR, or do I have to reinstall OSX and Ubuntu?
If the problem is an unusable MBR sector on sda, there is a procedure which may fix that.
It was done using Macosx, but can be done from a Ubuntu live cd.
It just writes a fake MBR to allow the refit partition tool to resync the MBR.
You can then install the refit package and run gptsync from the Live CD.

You first need to check the state of the sda MBR sector by doing a hexdump to see if this applies to you, it may not.

There is a record of a succesful fix using my posts in these links, you need to read around these posts for the full story..

Re: 8.04 cleared the MBR partition table
http://ubuntuforums.org/showpost.php...5&postcount=24

http://ubuntuforums.org/showpost.php...8&postcount=30
(attached dummymbr.txt)

http://ubuntuforums.org/showpost.php...0&postcount=37