Change from Apple Partition Map to GUID

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sagarchandratrey
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Joined: Tue Jul 21, 2009 11:32 pm

Change from Apple Partition Map to GUID

Post by sagarchandratrey »

Hi all..
I tried installing the KDE based ROSA Marathon on top of already exisiting Linux Mint Cinnamon(13),Deepin and Linux Mint 12.

While installing ROSA,the GRUB seems to have had some issues because of which I was not able to boot into any of these OSes..I could not see the GRUB entries at all...I used a LIVE USB to check if the partitions were intact...

Used TESTDISK for checking the partitions..I can see the old partitions under the Mac Apple Partition Table but cannot recover anything from there.

Is there any way I can change the Partition map from Apple to something readable by a Live USB..I really need the data in one of the partitions.

Please help...!!!!

Thanks in advance !
srs5694
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Joined: Mon Feb 27, 2012 1:42 pm

Re: Change from Apple Partition Map to GUID

Post by srs5694 »

The Apple Partition Map (APM) is a partitioning system used by Apple on its 680x0 and PowerPC Macs, and on a few more specialized devices (such as TiVos). APM is equivalent in function to an MBR partition table or a GUID Partition Table (GPT), but it's incompatible with them.

It sounds like you were installing over an existing system, so the question of whether the disk ever used APM is best answered by asking which platform you're using. If it's an x86 or x86-64 computer, it's extremely unlikely that the disk used APM partitions. If it's a PowerPC Mac, then chances are it did use APM.

Based on the situation you described (a boot problem), TestDisk is the wrong solution, at least at this point. It's conceivable that a partitioning error is involved, but if so, TestDisk is the solution of last resort. You should first check your partitions with a general-purpose partitioning tool like GNU Parted, fdisk, or gdisk. A boot problem might not even have a partitioning error as the cause, though; it could be that the boot loader needs to be re-installed.

To move forward, I recommend you download the Boot Info Script and run it from an emergency boot disc. The script will produce a file called RESULTS.txt with details of your partitions and boot loader configuration. Post the RESULTS.txt file here, either as an attachment or between code tags to preserve the file's formatting. That will give us the information we need for a better diagnosis of your problem. Do not attempt to use TestDisk to recover anything; that's more likely to make it worse than to help. Do not attempt to convert the disk from MBR or GPT form to APM form; that's unlikely to be necessary, and an attempt to do this could end up trashing your disk.
sagarchandratrey
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Joined: Tue Jul 21, 2009 11:32 pm

Re: Change from Apple Partition Map to GUID

Post by sagarchandratrey »

Hi srs
Thanks for the reply.

I could solve the problem using the second entry in Testdisk..i.e the EFI GPT Partition Map.

I hardly understand the details of the entries on the screen but I could view and recover the partitions using the EFI GPT option.

Now all the OSes including the one which had created the problem(ROSA Marathon) are working fine :)

Thanks
Sagar
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