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Another thing...after ubuntu installation..refit partition tool did not
complain about partition table syncing...it said everything was already
in sync.

-- 
Partition Table is cleared during install on Intel Macs
https://bugs.launchpad.net/bugs/222126
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Status in grub-installer: Invalid
Status in Mactel Support: Fix Released
Status in “parted” package in Ubuntu: Fix Released
Status in “ubiquity” package in Ubuntu: Invalid
Status in parted in Ubuntu Hardy: Fix Committed
Status in ubiquity in Ubuntu Hardy: Invalid
Status in parted in Ubuntu Intrepid: Fix Committed
Status in ubiquity in Ubuntu Intrepid: Invalid
Status in parted in Ubuntu Jaunty: Fix Released
Status in ubiquity in Ubuntu Jaunty: Invalid

Bug description:
Binary package hint: ubiquity

Ubuntu 8.04 Final

Intel Macs have an EFI system and a GPT. The installer seems to handle the GPT correctly (as it has in the past), but it has recently come up that the installer is completely emptying the contents of the MBR partition table which is still required to boot Windows and Ubuntu (GRUB relies on the MBR partition table). The two tables are not synced automatically.

When users install Hardy, they are suprised to find that the system is unbootable (the EFI loader cannot "see" the partition as bootable). a tool such as rEFIt or gptsync can copy the information in the GPT into the MBR table thus fixing the issue (for most). 

This is even more serious for users with other working OS installs in addition to Ubuntu (such as other linux distros and Windows) since it completely dumps the information needed to boot these installs as well.

The expected procedure (and how the previous Ubuntu install seems to have handled it) is to 'update' both the GPT and the MBR table with changes instead of completely losing the information stored there.

gparted / parted seemed to update both tables properly previously as well.

I will be doing a full install on my iMac later and will be able to add additional information.


This bug was fixed in parted 1.8.8.git.2008.03.24-11.1ubuntu6 by adding "Apple Inc." as an additional system-manufacturer tag for which we do the special Apple GPT->MBR handling. Here are patches for hardy-proposed and intrepid-proposed:

  http://launchpadlibrarian.net/27503646/hardy.diff
  http://launchpadlibrarian.net/27504724/intrepid.diff

TEST CASE: You'll need a reasonably new Intel-based Mac system for which 'sudo dmidecode -s system-manufacturer' returns "Apple Inc." (not "Apple Computer, Inc."). Check that installations work, and that 'sudo fdisk -l' shows a reasonable MBR representation of the first four partitions on your disk (compare against 'sudo parted -s /dev/sda print').

REGRESSION POTENTIAL: The only other systems that really care about this kind of thing are ones for which 'sudo dmidecode -s system-manufacturer' returns "Apple Computer, Inc."; installations on those systems should keep working. Other than that I think we're basically taking a completely broken case and rendering it at least vaguely functional ...