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Cannot locate the Mac osx boot volume

When I try to go back to mountain lion from windows xp, the message is COULD NOT LOCATE THE MAC OSX BOOT VOLUME.


ONLY WINDOWS SHOWS IN BOOTCAMP.


TRIED DOWNLOADING BOOTCAMP 3.3 BUT IT WOULD NOT OPEN AFTER I DOWNLOADED IT.


INSTALLED MOUNTAIN LION YESTERDAY

MacBook (13-inch Late 2009), Mac OS X (10.7.4)

Posted on Jul 27, 2012 5:28 PM

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Posted on Jul 27, 2012 5:48 PM

Reboot, hold the option key down at the sound of the chime (not before) , continue to hold it until the boot manager appears, select OSX.


If there is no selection for OSX, post back

13 replies

Jul 28, 2012 8:14 AM in response to Ajfalc

You would need to restore 10.5 probably to install XP and go through the swamp land again.


TimeMachine is not bootable of course you could slice out 30GB and install OS X 10.5 on it or the other drive.


And hopefully you planned ahead and kept the Lion or ML installer packages before they were deleted.


You are going to need XP CD.


What more do you need to know to do?


That or get Windows 8 Preview and use that, it is free.


But you need to start over and rebuild your system(s).

Jul 28, 2012 9:25 AM in response to The hatter

This is not true.


Mountain Lion still allows pre-existing Windows XP, new installations require Windows 7.

http://www.apple.com/osx/specs/


Nothing has changed with respect to partitioning.


This sounds like either NVRAM corruption, or a bless problem, and neither the EFI startup disk selector nor the Apple provided startup disk for Windows app, are finding the installed Mac OS X system. I suggest zapping PRAM on startup, command-option PR, to clear NVRAM. And then hold down the option key alone on the next startup and tell us exactly what icons you see. If only Windows, then your options are to either start from scratch and restore from backups - or try moving forward and seeing if the problem can be repaired.


To do that, you need to boot from another Mac OS volume: any will do, Recovery HD, a USB disk, doesn't matter what OS it is, 10.6, 10.7, 10.8 are all fine. I want to see what the partition maps look like so you'll need to go to Terminal and report back the results from:


sudo gpt -r -vv show disk0

sudo fdisk /dev/disk0


These are read only commands, they don't alter the disk.

Jul 28, 2012 9:58 AM in response to The hatter

I don't know the exact mechanism by which either the hybrid MBR or GPT are getting munged, but it's effectively data loss. Hybrid MBRs are fragile, flaky, depart from the UEFI spec, and depart from Apple's own developer notes to avoid using them or data loss can ensue. And data loss is exactly what happens, way too often, with Boot Camp configurations. It's why I don't recommend them, and suggest people use a VM instead whenever possible.


As for fixing this problem, I disagree there is no way back. That's true for people who aren't very familiar with MBR and GPT. The problem is repairable without using that sledghammer of starting over. I suggest more familiarity with repairing, rather than replacing.

Jul 28, 2012 11:51 AM in response to The hatter

I have a snow leopard disc from my late 2009 MacBook.


I am mainly concerned with getting my OS up and running so I can go back to work. I can deal with the windows issue later.


Can I load the snow leopard on the partition that has windows and then reinstall my files from my backup drive.


If that works, I can probably reinstall mountain lion from the app store.


What do you think.


Thanks.

Jul 28, 2012 12:12 PM in response to Ajfalc

I think it's a mess, and you're just making more of a mess by installing Snow Leopard on the Windows partition. If you're willing to do that, why not just repartition the whole disk and install Lion clean?


I still suggest you zap PRAM. And boot from Recovery HD or another boot disk and see if it finds your Mac OS volume and can repair it. If not, I still think you should provide the results from this:


sudo gpt -r -vv show disk0
sudo fdisk /dev/disk0

Jul 28, 2012 12:18 PM in response to Ajfalc

Clone saves your system, lets you restore back so you are up and running.


If you can't boot OS X you can get started by creating an emergency OS X partition on external and use that.


Your internal main drive though needs to be returned to a functional partition for OS X and healthy partition table.


Lion Recovery or ML allow checking the health of hidden partitions.


Having a clone of your system at all times or any time makes it quick and easy to be back up and running and depending on speed and size of your hard drive and system, a full restore of OS X in an hour.


Emergency 30GB

Clone of full system 30-120GB

Windows system restore image(s) 60-200GB

Clone of home folder if desired 200GB, optional, could be just system - I just don't rely on TM only in any case

TimeMachine 350% the size of your Mac system and data (1.5TB or less)


A 2TB drive - not ideal to have all on one drive but could be one backup set.


Update of clone takes 15 minutes generally to keep it current.

The emergency system is like your own Recovery only has any other programs and utilities and full up to date of Apple OS only plus 3rd party drivers in order to function.

Cannot locate the Mac osx boot volume

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