12 Replies Latest reply: Feb 2, 2013 1:02 AM by BoHick
BoHick Level 1 (0 points)

Greetings Folks,


I am on a mid-2012 MacBook Pro 13 that received a few days ago so first ever post on a Mac forum - hope it's as friendly and useful as the one over at Lenovo.


Just came back to Mac. Long story, boring details, but in addressing an 18-month old tantrum and in a Homer moment I was being inattentive and converted my HD to dynamic under Windows 7 while trying to convert a partition to exFAT for sharing files.


Like some noob fool I did not make recovery disks at the get go and the fact that there were no disks shipped with the machine didn't register as it should have (my only complaint regarding the product - the rest is ALL my bad). And no, also like some noob fool I did not, having seen it for the first time, tuck anything into Time Machine either. So it's the short and curlies for me...ah yes, and under Internet Recovery when I tried to access the installation and recovery option in Safari, it told me there is no machine registered under my name, something I thought was addressed when I first accessed updates and etc. from the AppStore.


To get on with it, I can't boot into OSX and I can't erase the HD uneder OSX Disk Utility either - I am in Viet Nam and internet is slow so everytime I resort to CMD R to get Internet Recovery it takes hours to load. Verify says the OSX Base Operating System is ok. Error messages I get:


"Couldn't modify partition map" when trying to erase the OSX partition for a reinstall of ML;


"Couldn't write installion information to disk" when trying to reinstall ML and no disk visible to select


From years dealing with Windoze I know that there's only a clean wipe and reinstall to go back to NTFS from dynamic, so I suspect I will have to completely wipe and reformat the HD. I already tried wiping the original partition under W7 but still can't get Disk Utility to do anything with it. So my question (assuming a fool is correct) is this:


What is the best tool to wipe and reformat the HD to something my MBP will then recognize and I can (go through the days it will likely take to download and) reinstall ML?


Or is there an easier, softer way? My Spidey Sense says no...



MacBook Pro, OS X Mountain Lion (10.8)
  • Kappy Level 10 (266,036 points)

    Drive Preparation and Installation for Mountain Lion


    1.  Restart the computer and after the chime press and hold down the COMMAND and R keys until the menu screen appears. Alternatively, restart the computer and after the chime press and hold down the OPTION key until the boot manager screen appears. Select the Recovery HD and click on the downward pointing arrow button. Select Disk Utility from the main menu and click on the Continue button.


    2. After DU loads select your hard drive (this is the entry with the mfgr.'s ID and size) from the left side list. Note the SMART status of the drive in DU's status area.  If it does not say "Verified" then the drive is failing or has failed and will need replacing.  SMART info will not be reported  on external drives. Otherwise, click on the Partition tab in the DU main window.


    3. Under the Volume Scheme heading set the number of partitions from the drop down menu to one. Click on the Options button, set the partition scheme to GUID then click on the OK button. Set the format type to Mac OS Extended (Journaled.) Click on the Partition button and wait until the process has completed.


    4. Select the volume you just created (this is the sub-entry under the drive entry) from the left side list. Click on the Erase tab in the DU main window.


    5. Set the format type to Mac OS Extended (Journaled.) Click on the Security button, check the button for Zero Data and click on OK to return to the Erase window.


    6. Click on the Erase button. The format process can take up to several hours depending upon the drive size.

  • Imp68 Level 4 (2,590 points)

    While booted into Internet Recovery, you should be able to repartition the drive.


    Select the drive itself >> partition on the right >> change current to 1 partion >> click option and check off guid partion table, click ok >> change name to something (Machintosh HD typically) >> format to Mac OS extended journaled >> apply.


    That should fix things and allow a fresh install.

  • Imp68 Level 4 (2,590 points)

    Sorry my response was late after Kappy's.  I was typing it on my iPod haha.


    Just to note a thing about Kappy's response, it won't work entirely as described under normal circumstances.  In his response, you're booting straight off the recovery partition.  Since that partition is in use and locked, when you go to partition, you'll receive an error about not being able to unmount the drive.  Also, a couple terms sound like an older DU and won't match what you see.


    It sounds like your system is going straight to Internet Recovery anyway, though.

  • Imp68 Level 4 (2,590 points)

    Oh, one other thing, steps 4 to 6 won't be necessary.

  • BoHick Level 1 (0 points)

    Folks, thx for the quick replies.


    Am indeed going straight to Internet Recovery - which for some reason is choking bandwidth and while the MBP is online everything else on the network is locked out.


    Imp68: when you say 'the drive itself' do you mean the partition OSX is on?  As mentioned I get the following when trying to do anything whatsoever with the OSX partition:


    "Couldn't modify partition map" when trying to erase the OSX partition for a reinstall of ML;


    "Couldn't write installion information to disk" when trying to reinstall ML and no disk visible to select


    I have to quit out of Safari to try the steps you mention in your first reply. Failing that I'll post back from my W7 machine to look at next steps.


    From a cpl other posts I found it sounds like the worst case scenario is trying to find someone with a Mac who will let me download a complete new install from the AppStore. Am I understanding that correctly?

  • BoHick Level 1 (0 points)

    When trying to partition the HD under DU & IR it says it can't because of the MBR from W7. Am going to research Windoze alternatives in terms of how to re-convert the disk to something that will allow me to format the HD.


    If anyone's aware of a disk utility that can be loaded from a bootable disc/USB media and would do a recover or reformat pls let me know. Man am I having a dumb day here...

  • BoHick Level 1 (0 points)

    to recap


    1] i'm going straight to Internet Recovery, which ***** all my bandwidth and i can't do my regular work while interfaced, but:

         a) Mac OSX Base System partition verifies as OK

         b) i can access Safari, etc.


    2] i can't perform any tasks in Disk Utility (as suggested by Kappy and Imp68):

         a) can't modify partition map

         b) can't erase or reformat any partitions or the HD (beacuse of course they are in use)


    3] i can't reinstall Mountain Lion through DU:

         a) can't write installation information to disk (i assume becuse it's the tiny Base System partition and no external drives are being recognized)

         b) no disks are visible to select for installation


    having asked for another route, a mehtodology/utility that can rectify the status of the drive (wipe and reformat to OSX for example) so that i can reintall there has been no further response.


    a bit perplexed as i would think this situation is one that would warrant some attn w negative replies to the suggested methodology


    so the question set i need answered at this point:


    if i completely wipe the HD will cmr r still bring me to Disk Utility? and, if so

    will i be able to reformat my HD; and if so

    will i then be able to reinstall OSX 10.8?


    and if not, what then?

  • Imp68 Level 4 (2,590 points)

    As it stands, you're not even booting off the hard drive to begin with.  You're booting into Internet recovery.  So wiping the drive won't matter.


    I find it really odd the drive can't be repartitioned.


    Just to recap, this should work:  From disk utilities, select the actual hard drive (this will be the one with the numbers: ex 500.11 GB etc).  Then click the partition tab on the right area.  Change the current layout to 1 partion, click options and be sure guid partition table is selected, format is set to Mac OS extended journaled, then apply.  When it's done, close du and then reinstall.


    This exact procedure doesn't work?

  • BoHick Level 1 (0 points)

    thx for clarifying where the boot is coming from - great feature to have access to


    i've printed out the entire thread and soon as the workday is done here  i'll restart IR and let you know if DU was able to do the job


    much of my work is internet-dependent and IR really does plug the pipe in the developing world so i have to address my stupidity on my own time

  • BoHick Level 1 (0 points)

    Imp68, thx for your patience since I (twice) misunderstood the protocol you were describing. And Kappy, thx for telling me exactly what to do off the get go...and I swear to never ever again start reading from the last word in the thread backwards and just skim (blindly, it seems - no wonder you had no more to say, Kappy) when i get to the beginning.


    No excuses, just a very humble thx and apology to both for unecessarily taking up your obviously valuable time. Once i got my PCfied brain around what you were saying and how ridiculously easy it was, well, how could it be that easy? Perhaps I have grown too used to having to wrestle with the OS all the time. The things needing ArcGIS and Access will drive a guy to sometimes.


    My machine says it will be done reinstalling in 6 hours...well...I just looked again and it says 11.5 and stopped climbing... Regardless, this would never be happening with any PC, even my trusty Lenovo S10 workstation.


    Hat in hand, once again, thx you two...I hope I don't have to trouble you again for a long, long time.

  • Imp68 Level 4 (2,590 points)

    Glad it seems to finally be working.

  • BoHick Level 1 (0 points)

    all good - and everything properly backed up this time - only took 16 hours ;-)