m0ng

Q: Partition pain

I was trying to free up some space from my windows 10 partition to go back to my Mac OS X 10.10.2 partition. You used to be able to do this in either boot amp or the disk utility just by dragging the sliders, I'm sure...i couldn't get it to work in Mac I looked online and read somewhere that Windows 10 could do it natively.

 

In Windows 10 disk management o resized the bootcamp partition to free up some space. This then created an empty partition, so I headed back to OS X, but it didn't seem to see it in disk utility, aback to Windows 10, I thought if I formatted it as fat32 os X would see it and be able to reclaim the space.

 

That's when the sh*t hit the fan:

 

-cant boot into os X

-cant boot into Windows 10

 

when booting the screen is black for a long time then the machine tries to book Windows but says there's no bootable media (or something similar).

 

I tries command + R to load online help/utilities but disk utility their recognises all the partitions but cannot seem to do anything with them, like delete or repair etc. It says it can't make changes to the boot map (apologies not exact mssage(s) have subsequntly been drinking to numb the misery of it. Am away from home, so don't have any bootable media Or any backups with me.

 

basically I've broken the guild map I think but because everything's greyed out in the utilises, I can't erase any partitions (if that's what I need to do).

 

would someone please give me some advice? - will it be possible to save the data on the os X partition? (Not so bothers about Windows 10)???

 

thanks in advance

 

david

 

Macbook pro retina 15inch 2012

Posted on Dec 28, 2015 9:10 PM

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Q: Partition pain

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  • by Loner T,

    Loner T Loner T Dec 28, 2015 9:22 PM in response to m0ng
    Level 7 (24,202 points)
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    Dec 28, 2015 9:22 PM in response to m0ng

    m0ng wrote:

     

    I was trying to free up some space from my windows 10 partition to go back to my Mac OS X 10.10.2 partition. You used to be able to do this in either boot amp or the disk utility just by dragging the sliders, I'm sure...i couldn't get it to work in Mac I looked online and read somewhere that Windows 10 could do it natively.

    This has never been supported. Please see Boot Camp: Resize the Windows partition . Snow Leopard was a bit more forgiving, but not many others.

     

     

    In Windows 10 disk management o resized the bootcamp partition to free up some space. This then created an empty partition, so I headed back to OS X, but it didn't seem to see it in disk utility, aback to Windows 10, I thought if I formatted it as fat32 os X would see it and be able to reclaim the space.

    Windows has no idea it is running on a Mac and overwrites the Mac EFI.

     

    would someone please give me some advice? - will it be possible to save the data on the os X partition? (Not so bothers about Windows 10)???

    Use OS X: About OS X Recovery - Apple Support and boot into Internet Recovery. Find a 16GB Flash drive, if you can, and How to install OS X on an external drive connected to your Mac - Apple Support and boot from this. Boot from this external disk, and we can inspect the internal disk for recoverability.

  • by m0ng,

    m0ng m0ng Dec 29, 2015 5:27 AM in response to Loner T
    Level 1 (61 points)
    iPhone
    Dec 29, 2015 5:27 AM in response to Loner T

    Many thanks for replying. I only have an 8GB USB key available. Is 16GB required because of el capitain or some other reason?

     

    d

  • by Loner T,

    Loner T Loner T Dec 29, 2015 8:59 AM in response to m0ng
    Level 7 (24,202 points)
    Safari
    Dec 29, 2015 8:59 AM in response to m0ng

    Try with the 8GB flash drive. If you run into any space issues, please post back.

     

    From How to install OS X on an external drive connected to your Mac - Apple Support

    Your external drive needs a GUID partition with at least 8 GB of available space to install OS X. For best results, the volume should be formatted as Mac OS X Extended format (not FAT, NTFS, or EXFAT).
  • by m0ng,

    m0ng m0ng Dec 29, 2015 11:57 PM in response to Loner T
    Level 1 (61 points)
    iPhone
    Dec 29, 2015 11:57 PM in response to Loner T

    Hi, as per your instructions, I e created a us A key version of mountain lion (the version it automatically downloaded).

     

    image.jpeg

     

    Have attached a screen shot (for some reason it's showing it sideways on here to me, hopefully you'll be able to see though).

     

    DIsk01 - my os X el cap partition

    disk02 - Windows 10

    disk03 - the partition space I was stupidly trying to reclaim for OS X from the Windows 10 partition.

     

    AS you (might) be able to see from the picture, all disks are now "partition type Windows_LDM"...

     

    please can can you advise as to what the next step would be to:

     

    A) see if I can recover at least my OS X (disk01) partition?

     

    and

     

    B) what to do next to just get the machine working again (with or with out the data on my partitions)?

     

    many thanks so far, much appreciated and hoping for good news

     

    d

  • by Loner T,

    Loner T Loner T Dec 30, 2015 1:22 AM in response to m0ng
    Level 7 (24,202 points)
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    Dec 30, 2015 1:22 AM in response to m0ng

    Your Mac originally shipped with Mountain Lion, which is why you were offered ML. Since you were on El Capitan before the problem started, can you upgrade the external USB to El Capitan, if possible, before we proceed further? There are significant differences between ML (10.8) and ELC (10.11) and it would better to avoid issues resulting from such differences.

  • by m0ng,

    m0ng m0ng Dec 30, 2015 7:43 PM in response to Loner T
    Level 1 (61 points)
    iPhone
    Dec 30, 2015 7:43 PM in response to Loner T

    Thank you once again for your reply.

     

    I managed to download ELC today. Despite what I thought, my USB key is 16GB but, with moutain lion installed from the recovery method, it says there is not enough room to install ELC. (I heading into town tmrw to try and pic up something bigger 32gb should be ok I hope..)

     

    In the meantime, I tried formatting disk03 partition (see pic from last post) to see if I could make that hfs+ and install ELC on there instead - however it tells me it cannot erase the partition or alter the GUID map. I'm sorry I forget the exact wording because it very already given up and packed up for tonight - perhaps this is because the partitions were made or alter under ELC or Windows 10??

     

    Now it seems more a question of if I'll ever get the machine working again, let alone see my data again that's on the disk01 partition...do you agree?

     

    I have a genius appointment on Saturday, but would like to fix it before then with your help if possible.

     

    Thanks again.

  • by Loner T,

    Loner T Loner T Dec 30, 2015 7:49 PM in response to m0ng
    Level 7 (24,202 points)
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    Dec 30, 2015 7:49 PM in response to m0ng

    Your disk, unless modified further, should be salvageable. In most cases, changing Partition GUIDs will allow the disk to work. This is the reason to put ELC on an external disk, with GPT Fdisk, so the GPT entries on the internal disk can be corrected.

  • by m0ng,

    m0ng m0ng Dec 30, 2015 7:59 PM in response to Loner T
    Level 1 (61 points)
    iPhone
    Dec 30, 2015 7:59 PM in response to Loner T

    Im sorry "GPT", "Fdisk"?

     

    when you have time and are able, could you assume I've got ELC on the external sd card I'm getting tmrw, and guide me on the next steps to hopefully recovering the partitions and data on them?

     

    cheers

  • by Loner T,

    Loner T Loner T Dec 30, 2015 8:18 PM in response to m0ng
    Level 7 (24,202 points)
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    Dec 30, 2015 8:18 PM in response to m0ng

    Once you have ELC on the SD Card, please also install GPT Fdisk - http://sourceforge.net/projects/gptfdisk/ .

  • by m0ng,

    m0ng m0ng Dec 31, 2015 4:58 AM in response to Loner T
    Level 1 (61 points)
    iPhone
    Dec 31, 2015 4:58 AM in response to Loner T

    HI,

     

    i realise it's New Year's Eve tonight and you will most probably be out enjoying yourself, (have fun). If you have time before you go, please note I've bought a 32gb sd card and am on my way home about to download gpt Fdisk. Please can you walk me through any special steps to getting ELC on the sd card or how I might use gpt to claim my partitions back?

     

    if you can't because you are busy, I fully understand. Hopefully somebody else with no plans tonight (like myself) will be available or I'll just have to wait.

     

    d

  • by sunmetis,

    sunmetis sunmetis Dec 31, 2015 5:35 AM in response to Loner T
    Level 1 (4 points)
    Dec 31, 2015 5:35 AM in response to Loner T

    HI LonertT ....On this new subject

     

    After the "partition fusion drive crash" I had to recreate the fusion drive. Ive reinstalled osx el capitan the windows 10 .

     

    I see the partition (bootcamp) click on format . And get the message

     

    we can(t create partition or find an existing. For more information clik on log (where is it ?)

  • by Loner T,

    Loner T Loner T Dec 31, 2015 8:12 AM in response to sunmetis
    Level 7 (24,202 points)
    Safari
    Dec 31, 2015 8:12 AM in response to sunmetis

    Can you post a new discussion and include the output of the following Terminal commands?

     

    diskutil list

    diskutil cs list

    sudo gpt -vv -r show /dev/disk0

    sudo fdisk /dev/disk0

     

    If you have a Fusion drive, please add the output of the following

    sudo gpt -vv -r show /dev/disk1

    sudo fdisk /dev/disk1

     

     

    The "sudo" commands will prompt for your password, and it will not be echoed back. You may also see a warning about improper use of "sudo" and potential data loss due to "abuse" of the command.

  • by Loner T,

    Loner T Loner T Dec 31, 2015 8:15 AM in response to m0ng
    Level 7 (24,202 points)
    Safari
    Dec 31, 2015 8:15 AM in response to m0ng

    1. Please use How to install OS X on an external drive connected to your Mac - Apple Support and get the OS X version shipped with your Mac.

    2. Upgrade the SD Card to El Capitan from the App Store .

    3. Once you have ELC on the SD Card, boot from it and install GPT Fdisk - http://sourceforge.net/projects/gptfdisk/ on the SD Card.

  • by m0ng,

    m0ng m0ng Dec 31, 2015 9:18 AM in response to Loner T
    Level 1 (61 points)
    iPhone
    Dec 31, 2015 9:18 AM in response to Loner T

    Thank you for your continuing help Loner. It is appreciated greatly!

     

    quick question: I have the el cap installer and now a blank 32gb sdxc card. I've formatted the card to hfs+. Can I just install el cap directly to the new card or do I *need* to go through the install OS X Mountain Lion (the version it came with) first?

     

    D

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