Mountain Lion Upgrade Dependency
It is important to check that the recovery partition exists before performing the upgrade from Lion to Mountain Lion. In testing the Gold Master (GM) release, I found that the installation will start and progress as expected until the system reboots into the installation boot. At that point, it will fail and you will be caught in a perpetual loop if your recovery partition is non-existant. Always make sure you have a recent backup before performing the upgrade or any of these steps.
Check first that the partition exists:
From terminal, “diskutil list” and look for a recovery partition.
$ diskutil list /dev/disk0 #: TYPE NAME SIZE IDENTIFIER 0: GUID_partition_scheme *750.2 GB disk0 1: EFI 209.7 MB disk0s1 2: Apple_CoreStorage 749.3 GB disk0s2 3: <strong>Apple_Boot Recovery HD</strong> 650.0 MB disk0s3
If you don’t see a partition named “Apple_Boot Recovery HD“, you will need to create it.
Steps to create the recovery partition:
- Download the Lion Recovery Update v1.0 http://support.apple.com/kb/DL1464.
- From terminal, mount the Lion Recovery Update disk image.
hdiutil attach ~/Downloads/RecoveryHDUpdate.dmg
- Expand the package from the Lion Recovery Update disk image.
pkgutil --expand /Volumes/Mac\ OS\ X\ Lion\ Recovery\ HD\ Update/RecoveryHDUpdate.pkg ~/Desktop/DelMe
- Attach the disk image for the recovery partition.
hdiutil attach ~/Desktop/DelMe/RecoveryHDUpdate.pkg/RecoveryHDMeta.dmg
- Create the recovery partition and copy it into place.
~/Desktop/DelMe/RecoveryHDUpdate.pkg/Scripts/Tools/dmtest ensureRecoveryPartition / /Volumes/Recovery\ HD\ Update/BaseSystem.dmg 0 0 /Volumes/Recovery\ HD\ Update/BaseSystem.chunklist
- Verify the recovery partition is in place. You should see a partition labeled “Apple_Boot Recovery HD“. You can verify it is functional by rebooting and holding the option key and booting into the recovery partition.
- Finally some cleanup steps.
hdiutil detach ~/Downloads/RecoveryHDUpdate.dmg hdiutil detach ~/Desktop/DelMe/RecoveryHDUpdate.pkg/RecoveryHDMeta.dmg rm -rf ~/Desktop/DelMe
Hopefully these steps will help prevent a bad upgrade experience. I am not sure how common it is to find you don’t have a recovery partition. In my case, I think it was because I restored my OS a couple times while testing the development releases. Good luck with the upgrade!
1. How can I create or recreate a Lion recovery partition? http://apple.stackexchange.com/questions/19145/how-can-i-create-or-recreate-a-lion-recovery-partition