How to?: GPT boot error (way(s) to get rid off)

Say Heading · Jun 9, 2011

I noticed several posts dealing with this issue. Maybe we can collect our workarounds here.
They may be very different and depending on whatever is causing it.

Let me start with what I had recently:

Situation:

"GPT boot error" displayed when trying to boot from a brand new formatted and freshly installed OS X hard disk.
Using a different hard disk´s bootloader and selecting the affected drive from chimera´s menu would end in a successful boot, but either having the corrupted drive as first in BIOS start sequence or selecting it during POST via F12 fails.

What did not help:

Reformatting, repartitioning via disk utility.

Successful:

Erasing the GPT (GUID partition table) via windows (7/XP/Vista).

1. Open CMD (enter the string "cmd" into window´s search function and <enter>).
2. Type "diskpart" (without quotes), <enter>, confirm security request.
3. Type "list disk" <enter> to obtain an overview of connected drives.
4. Type "select disk number" <enter> (where "number" represents the number of the drive that you intend to erase) to select the desired drive.
5. Type again "list disk" <enter>. The previously selected drive should now show to be selected by a "*" in front of it.
6. Type "clean" <enter> to erase the drive. Completion will be confirmed by a message (that I don´t know the English equivalent). The protected GPT partition is now erased.
7. Type "exit"<enter> to leave diskpart.

When booting back into OS X you can now reformat/partition the drive as usual and install a new GPT partition using MultiBeast or any other tool.

Side notes:

This - of course - will delete all your data o the effected disk.
Nice to have a backup in advance.
But rather don´t try to use a recovery disk image via disk utility.
I did that in my first attempt (creating the img file took 7+ hours, read only, not encrypted!), but had to realize that obviously the corrupted GPT partition was part of the backup - and was restored :banghead:

I just reinstalled everything, but I guess a copy tool which does not copy the GPT would do it as well. Don´t know what CarbonCopyCloner would do.

I´m shure there is an OS X internal solution via terminal available as well.
But I don´t know it (yet).

10terabyte · Jun 29, 2011

Thanks for this. I am having the same error, so I am following your advice. Will report back on how it goes.

-Chris :thumbup:

10terabyte · Jun 29, 2011

I found that my problem was directly related to the HDD its self. I was using a new advanced format drive. On top of that, it was one of the Opal self encrypting drives. Rubbish.

I went back to an 80 GB WD and it installed fine. At least I know my setup is ok now.

Now, on to fixing video drivers.

Geithals · Sep 19, 2011

I hope it's okay to reply to an old thread but I'm sure it's still a buggy issue for some. Thanks to Say Heading for his clear instructions on solving this thorny issue.
I had the problem with a new 2tb disk, couldn't get past the GPT boot 0 error and tried all the fdisk et.c. stuff and god knows what else.

I formatted it into fat32 with disk utility and then followed Say Heading's instructions for using diskpart, it still didn't work.
Then I tried again, this time no disk utility fat32 format but leaving the disk in GUID. I used diskpart to clean it and it worked fine after that, boots up on his steam. Then I read the description of the "clean" command in 'diskpart'. It approaches a MBR format disk differently than a GUID format. With a MBR disk, only the MBR information and the hidden sector info is overwritten . But with a GUID disk the GPT partitioning info including the Protective MBR, is overwritten. There is no hidden sector info.
There are 2 ways to skin this cat and it only worked for me with using diskpart on a Guid Partition Table (GPT) disk. I hope this helps some folk.

Going Bald · Sep 19, 2011

Another thing you can try is to boot with a linux live dvd of some flavor (Ununtu works ok). At the Ubuntu desktop, open a terminal.
use ls command to identify the hard (best to have only SO X hd connected when you do this so there is no doubt)
unmount the hard drive
install the boot 0 and boothfs files to the hard drive boot sector and the partition sector (boot is already in your OS X root, so you don't need to install it here)
exit terminal and shutdown Ubuntu.
Boot and quickly remove the live DVD if you have cd/dvd as first in your boot order
you should now get to the chameleon boot screen

hardmantosh · Sep 19, 2011

Say Heading said:
I noticed several posts dealing with this issue. Maybe we can collect our workarounds here.
They may be very different and depending on whatever is causing it.

Let me start with what I had recently:

Situation:

"GPT boot error" displayed when trying to boot from a brand new formatted and freshly installed OS X hard disk.
Using a different hard disk´s bootloader and selecting the affected drive from chimera´s menu would end in a successful boot, but either having the corrupted drive as first in BIOS start sequence or selecting it during POST via F12 fails.

What did not help:

Reformatting, repartitioning via disk utility.

Successful:

Erasing the GPT (GUID partition table) via windows (7/XP/Vista).

1. Open CMD (enter the string "cmd" into window´s search function and <enter>).
2. Type "diskpart" (without quotes), <enter>, confirm security request.
3. Type "list disk" <enter> to obtain an overview of connected drives.
4. Type "select disk number" <enter> (where "number" represents the number of the drive that you intend to erase) to select the desired drive.
5. Type again "list disk" <enter>. The previously selected drive should now show to be selected by a "*" in front of it.
6. Type "clean" <enter> to erase the drive. Completion will be confirmed by a message (that I don´t know the English equivalent). The protected GPT partition is now erased.
7. Type "exit"<enter> to leave diskpart.

When booting back into OS X you can now reformat/partition the drive as usual and install a new GPT partition using MultiBeast or any other tool.

Side notes:

This - of course - will delete all your data o the effected disk.
Nice to have a backup in advance.
But rather don´t try to use a recovery disk image via disk utility.
I did that in my first attempt (creating the img file took 7+ hours, read only, not encrypted!), but had to realize that obviously the corrupted GPT partition was part of the backup - and was restored
I just reinstalled everything, but I guess a copy tool which does not copy the GPT would do it as well. Don´t know what CarbonCopyCloner would do.

I´m shure there is an OS X internal solution via terminal available as well.
But I don´t know it (yet).

maybe then this will help:::

http://www.rodsbooks.com/gdisk/
and also http://developer.apple.com/library/mac/ ... index.html

good idea on creating a thread on this; :thumbup:

well done and heres the stuff but its not allowed upload..edit

Geithals · Sep 20, 2011

Reading from those 2nd links about the GPT utility, is there a command line in that utility that will do what diskpart does when it is ordered to clean a GPT disk , namely overwrite the Protective MBR and make it ready to install a new (bootable) GPT partition?

hardmantosh · Sep 20, 2011

Geithals said:
Reading from those 2nd links about the GPT utility, is there a command line in that utility that will do what diskpart does when it is ordered to clean a GPT disk , namely overwrite the Protective MBR and make it ready to install a new (bootable) GPT partition?

Its up to you to click on the links provided and other links inside those.

[ I cant answer an open question like that ] you could be wanting to do many things..

Geithals · Sep 23, 2011

hardmantosh said:
Geithals said:

Reading from those 2nd links about the GPT utility, is there a command line in that utility that will do what diskpart does when it is ordered to clean a GPT disk , namely overwrite the Protective MBR and make it ready to install a new (bootable) GPT partition?

Click to expand...

Its up to you to click on the links provided and other links inside those.

[ I cant answer an open question like that ] you could be wanting to do many things..

It isn't an open question, it's the question that this thread is built upon. GPT boot error and ways how to get rid of it.
It might be more convenient for some folk if they can use a command line in the Terminal to remove the protective MBR, rather than use diskpart in Windows. I have read through much of the info from the 2 links.
The closest I can get is the command line
gpt create [-f] device ...
The create command allows the user to create a new (empty) GPT.
By default, one cannot create a GPT when the device contains a
MBR, however this can be overridden with the -f option. If the
-f option is specified, an existing MBR is destroyed and any par-
titions described by the MBR are lost.

Going Bald · Sep 23, 2011

If you run disk utility and select your hard drive (not the partition), then select the erase button, then the security options button, it will open a window and let you move the slider to the right to increase the number of times it will write zero's to the HD. It destroys all formatting and gives you a totally blank hard drive. 1 pass is enough for all practical purposes and 7 passes is more than enough unless you are really paranoid about erasing data. 30 passes and I don't think any recovery system available will recover anything from the drive.

When it is done, it creates the boot sector for the hard drive, either GUID, Apple OS or MBR, whichever one you selected at the beginning and allows you to name the drive.

Note that it is impossible to do this to the drive you booted to your OS X install with. It must be a different drive.

Search

How to?: GPT boot error (way(s) to get rid off)

Say Heading

10terabyte

10terabyte

Geithals

Going Bald

Moderator

hardmantosh

Geithals

hardmantosh

Geithals

Going Bald

Moderator

Forum

Guides

Downloads