Installing Ubuntu 12.04 on EFI system

Solution 1:

Your parted output suggests you've got a partition table problem, or at least an issue that libparted (which is used both by the text-mode parted program and the Ubuntu partitioner) is interpreting as a partition table problem. The "Invalid or incomplete multibyte or wide character" message suggests that parted is having problems interpreting the partition name, which is officially a UTF16-encoded name. Unfortunately, the last time I checked, parted didn't do proper UTF-16 encoding or decoding of partition names; instead, it tried to interpret them as a sort of modified ASCII -- or in practice, a modified UTF-8. This could lead to problems if a real UTF-16 partition name used non-ASCII characters, since they might then look like gibberish when interpreted as a modified UTF-8. Since libparted is very sensitive to errors and offers little in the way of corrective tools, the result is an error, as both parted and the Ubuntu installer demonstrate.

If I'm right (and I'm far from certain that I am), you should be able to correct the problem as follows:

1. Boot into the Ubuntu (or any other Linux) rescue disk.
2. If necessary, download and install GPT fdisk (gdisk). It's available as the gdisk package in Ubuntu.
3. Type sudo gdisk /dev/sda to launch gdisk on your problem disk.
4. Type v to verify the disk's data structures. If gdisk reports any problems, it could be that parted was reacting to some problem other than the partition name, and that may need to be dealt with instead of (or at least before) proceeding with the below steps.
5. Type p to view your partition table. Look for any non-ASCII characters in the "Name" column.
6. Type c to change the name of any partition that has a strange name. You'll be asked for a partition number and a new name. Repeat this for as many partitions as necessary (up to all of them).
7. Type p to review your partition table to be sure everything looks sane.
8. If everything looks good, type w to save your changes and exit from gdisk.

If my suspicion is correct, you should now be able to proceed with Ubuntu installation. If I'm correct, this is a libparted bug, which should be reported to Ubuntu and/or to the libparted developers. Recording the names of all your partitions for inclusion in your bug report is worth doing.