Crisis - formatted efi partition.

[Grant]

What would help is if @grantza could describe what were the partition sizes before the problem, for example: how big was the Mac and Windows partitions: the analysis shows this to be 200Mb for EFI (which btw is the standard size), 284Gb for the Mac partition, and 36Gb for the Windows partition; all totaling to 320Gb.

If this is correct then the next step I'd recommend is recreating the correct partition map with pdisk (and only if that fails, revert to gpt)

apologies for the delay

those are the correct sizes.
i clearly recall when creating a partition for windows via boot camp only allocating about 40GB for windows, as windows would only be used on rare occasions.

i booted from an ubuntu disk last night
however downloading ubuntu programs confuse me no end, they seem to be in bits & pieces, like a jigsaw that needs to be assembled - but probably doing something wrong.

 

[ponder]

i booted from an ubuntu disk last night
however downloading ubuntu programs confuse me no end, they seem to be in bits & pieces, like a jigsaw that needs to be assembled - but probably doing something wrong.

Installing software in linux is simpler than win or osx, 99% of stuff comes from the same central repository and there are several ways in ubuntu to install them, software center, synaptic and apt-get via cli.

 

[Grant]

Installing software in linux is simpler than win or osx, 99% of stuff comes from the same central repository and there are several ways in ubuntu to install them, software center, synaptic and apt-get via cli.

in there any manual fan control program that one can use when booting from an ubuntu cd ?

i found last night, booting from the cd, the mbp got real real hot

 

[Grant]

Paragon Hard Drive Manager

Someone suggested I download a trial of this program - which apparently is able to convert MBR to GUID.

I took a look, and the following option was presented:



So, it would appear that it is capable of doing the conversion & leaving existing data intact.
I was wondering if anyone had any experience with this program & if so, did it work for them.

**edit
not sure why mybb converted that image to a minuscule size - tried png & jpg - no difference !

 

[[)roi(]]

Someone suggested I download a trial of this program - which apparently is able to convert MBR to GUID.

I took a look, and the following option was presented:
View attachment 94961


So, it would appear that it is capable of doing the conversion & leaving existing data intact.
I was wondering if anyone had any experience with this program & if so, did it work for them.

**edit
not sure why mybb converted that image to a minuscule size - tried png & jpg - no difference !

From the TestDisk analysis, your problem did not appear to be isolated to only the EFI partition; IMO Windows overwrote some other bits in the partition map, specifically affecting EFI and HFS+ partitions.

To fix this I'd still suggest tackling the problem from the OS X side, rather than Windows.

Badically I suggest following the article I provided you that detailing the TestDisk followed by pdisk process. Btw the changes shown using pdisk are isolated to the partition map so if it doesn't work you can always revert by using pdisk to reset the partition map back to the current settings.

Also when running TestDisk, don't forget to create a log to ensure you have a physical record of both the current map and analyzed partition values.

 

[Grant]

Problem Solved convert MBR to GUID

So, it is over - well almost !
Paragon Hard Drive Manager sorted the problem out.

MBP now boots happily again into the Mac OS - all data remained intact.

HOWEVER, paragon did warn me that once it converted the drive back from MBR to GUID, 32bit versions of Windows will not boot.
I am pretty certain there must be a easy way around it, although I am not particularly concerned.
If anyone has ideas as to the easy way to sort that out, please don't be shy about it.

Thanks to those who stuck by me through this one, & in particular [)roi(] .

 

[[)roi(]]

So, it is over - well almost !
Paragon Hard Drive Manager sorted the problem out.

MBP now boots happily again into the Mac OS - all data remained intact.

HOWEVER, paragon did warn me that once it converted the drive back from MBR to GUID, 32bit versions of Windows will not boot.
I am pretty certain there must be a easy way around it, although I am not particularly concerned.
If anyone has ideas as to the easy way to sort that out, please don't be shy about it.

Thanks to those who stuck by me through this one, & in particular [)roi(] .

Excellent news!

So what exactly is the problem with the Windows partition (+ just to confirm that's bootcamp)?

What happens when in OS X you choose to reboot into Windows, is that what is currently failing? Could you describe it bit a more.

On a side note you seem to imply that Windows probably wasn't that important; so if that's the case; did you ever try to rather run it in a VM as opposed to bootcamp?
Ps. ignore the question, if you needed bootcamp for Windows gaming?

 

[Grant]

Excellent news!

So what exactly is the problem with the Windows partition (+ just to confirm that's bootcamp)?

What happens when in OS X you choose to reboot into Windows, is that what is currently failing? Could you describe it bit a more.

On a side note you seem to imply that Windows probably wasn't that important; so if that's the case; did you ever try to rather run it in a VM as opposed to bootcamp?
Ps. ignore the question, if you needed bootcamp for Windows gaming?

From within mac, if i go to system preferences > startup disk, i am given the choice of mac or windows.
If i select windows, the mbp reboots, and attempts to start windows, but an error message is returned:
"no bootable device - insert boot disk & press any key"

I do need a windows os for certain work I do, not gaming, running via VM does not work for me - too cumbersome (imo).
The windows partition is not much more than the OS itself, MS Office & a couple of other programs - no data kept in there.
So using boot camp to delete the partition & reinstall os no big deal, but would rather, if possible, get windows bootable again.
Perhaps when next I boot (or attempt to) into windows & it asks for a boot disk, I'll pop the Win7 dvd in an see if it wants to try repair or do a full install.

 

[sajunky]

You can try to repair boot record on Windows partition. Or just mark Windows partition active (I don't know whether it matters with your boot manager).

 

[[)roi(]]

This post has the solution: http://superuser.com/questions/374372/how-do-i-make-my-boot-camp-partition-bootable-again

Basically you need rEFIt

Ps. Try to avoid the Windows disk utilties & definitely don't mark the partition as active in Windows, or make any other changes.

 

[ponder]

**edit
not sure why mybb converted that image to a minuscule size - tried png & jpg - no difference !

To stop people from posting annoyingly large images. The proper way to do it is to use thumbnails people can click on if they wanna see the larger image. Posting large images is not on.

 

[Grant]

This post has the solution: http://superuser.com/questions/374372/how-do-i-make-my-boot-camp-partition-bootable-again

Basically you need rEFIt

Ps. Try to avoid the Windows disk utilties & definitely don't mark the partition as active in Windows, or make any other changes.

interesting
rEFIt was installed, somehow the last time i booted into windows rEFIt did not appear, this time it did, booting into Win7 without issue.

 

[[)roi(]]

interesting
rEFIt was installed, somehow the last time i booted into windows rEFIt did not appear, this time it did, booting into Win7 without issue.

Hope that means all the problems are solved?

 

[Grant]

Hope that means all the problems are solved?

all is solved !

 

[Seriously]

all is solved !

A nice summary tutorial and sticky would be wonderful for future reference!

 

[Grant]

A nice summary tutorial and sticky would be wonderful for future reference!

the title is incorrect tho, after much digging i discovered it was not a problem with the EFI partition, it was the entire drive's file system that accidentally got converted from GUID to MBR.

so it was a matter of reverting the entire drive back to GUID from MBR

but yes, it would be of value to others, i googled like crazy, but there was not too much info on this particular problem & how to easlily resolve it

 

[bwana]

the title is incorrect tho, after much digging i discovered it was not a problem with the EFI partition, it was the entire drive's file system that accidentally got converted from GUID to MBR.

so it was a matter of reverting the entire drive back to GUID from MBR

but yes, it would be of value to others, i googled like crazy, but there was not too much info on this particular problem & how easlily resolve it

Apart from formatting and restoring from a backup?

Was the juice worth the squeeze?

 

[Grant]

Apart from formatting and restoring from a backup?

Was the juice worth the squeeze?

yes 1000%

it's always quick and easy to say format & restore from backup, but for that to really be easy one needs a clone of the entire drive - everything on it.

so in this case, formatting & restoring would involve:
installing the mac os
installing system updates
installing the multiple programs on it
configuring all those programs
getting all the setting back to how you prefer on various media players etc
setting up connected devices
restoring data to its original locations

then:

running boot camp & installing the windows os
installing system updates
installing the multiple programs on it
configuring all those programs
getting all the setting back to how you prefer on various media players etc
setting up connected devices
restoring data to its original locations

so, indeed, it was definitely worth it, formatting & restoring in reality is never as simple & easy as it may sound when said quickly.
in my case, i already had a clone on an ext drive, hence me being able to boot from it, but still, never really as simple as it may sound.

 

[[)roi(]]

Apart from formatting and restoring from a backup?

Was the juice worth the squeeze?

If you know what you're doing a recovery like this can be fairly quick (a few minutes).

... that being said, it's still preferable to maintain backups.

 

[[)roi(]]

the title is incorrect tho, after much digging i discovered it was not a problem with the EFI partition, it was the entire drive's file system that accidentally got converted from GUID to MBR.

so it was a matter of reverting the entire drive back to GUID from MBR...

Just for clarity; your problems were isolated to the partition map; both your file system's tables and data were untouched.