Using a second partition to perform a clean install of mountain lion

Discussion in 'OS X Mountain Lion (10.8)' started by ritzer3, Jan 3, 2013.

  1. ritzer3 macrumors newbie

    Jan 3, 2013
    I have a mid-2010 mbp, which by now has seen a couple years of installs, downloads, boot camps, virtual machines, OSX updates etc. My once blazing fast pride and joy macbook has been reduced to a bit of an embarrassment, crashing often, taking centuries to open office, finder, firefox, chrome (!) etc and has basically become shadow of its former self. i.e. I wan't to start afresh, with a clean, fast gleaming OS which i can once again be proud of.

    I have about 70 Gb of music, 50 Gb in iTunes which I would like to keep and 20 Gb that I want to lose (music I foolishly didn't delete properly when cleaning out my libraries). I also have 20 Gb of pictures I'd like to keep.

    However, I do not have and cannot afford an external hard drive (I am a student who has no spare money) so have devised a plan to which I can avoid using an external hard drive, here goes:

    Firstly im planning to free up 70 Gb of space on my HD, turn it into a partition, erase it, and install mountain lion onto it, (which I'm hoping will result in a dual boot system (probably not, so how would i do that?))
    From there hopefully i can boot back into my old partition and consolidate my iTunes library over to the new partition, therefore keeping the music I have organised and discarding the rest (will that work?).
    Then I could delete all the music on my old partition, giving me loads of space which I could extend my new partition into (will that work?).
    I then plan to move all the pictures and any other stuff i want into the new partition and delete the old partition completely, extending the new partition to fill the drive, leaving me with a new install, with my music and pictures and no sluggishness!

    I am hoping that somebody here will be able to look over my plan, tell me I am a complete idealistic idiot and calmly inform me how it will work in the real world :D and upon doing it right I will write a step by step for people who want to do it too.

    Thanks a bunch
  2. torana355 macrumors 68030

    Dec 8, 2009
    Sydney, Australia
    Won't work, when you create your partition it will erase the whole disk. It can be done but not with Disk Utility. You need a app like iPartition which supports non-destructive resize of HFS+.
  3. ritzer3 thread starter macrumors newbie

    Jan 3, 2013
    Thankyou sir,
    So with respect to booting back into my first partition, does iPartition have the capability to allow me to do that? And I'm assuming I will need iPartition installed on both partitions?
  4. torana355 macrumors 68030

    Dec 8, 2009
    Sydney, Australia
    I have not used iPartiton personally but im positive it can achieve what you want. That being said you should just try to borrow an external drive, its much safer to back your files up to a separate drive.
  5. benwiggy macrumors 68020

    Jun 15, 2012
    Firstly, you can reinstall ML onto your existing hard drive, and it will keep all your data intact, and also make sure the system is tip-top and as it should be.

    Secondly: You need a backup!! If you don't have a backup, you will lose your files. Hard drives corrupt or break; computers get stolen and catch fire.

    I would not advise any repartitioning of your hard drive without a backup of your files. Backup your files onto a succession of DVDs if necessary.

    A clean install is usually "overkill" for fixing problems with your Mac. It's usually only necessary if you've deleted or altered system files. There are many other less drastic ways of trouble-shooting problems. I have a 2006 iMac that I've upgrade-installed 3 new OSes onto, over six years, and never once done a clean install. It still purrs like a kitten.
  6. Fishrrman macrumors G5


    Feb 20, 2009
    "However, I do not have and cannot afford an external hard drive (I am a student who has no spare money)"

    Can you scrape up, say, $20-25?

    If so, get one of these gadgets:,k:usb3+sata+dock
    (many items shown, they all work the same, just pick one you like that's cheap)

    Since you're a student, you may be able to "ask around" and scrounge up a used SATA "bare drive". I'm sure you can find a pre-owned one available cheap or free somewhere on campus.

    With those two things, you now have enough hardware to create a reliable backup system.

    You may or MAY NOT be able to partition your internal drive as you want without having an external drive available. Just be forewarned.

    The proper way to do what you are talking about is to:
    1. Get a backup drive "in-hand" (like the setup above)
    2. Use the free version of CarbonCopyCloner (version 3.4.7, available on the CCC download page) to clone the contents of your internal drive to the backup.
    4. Use Disk Utility to re-initialize the internal, and partition if desired.
    5. Install a "fresh" system and then import and/or copy over the data you wish to keep, or
    5a. "Re-clone" the backup back to the internal

    I have an April 2010 MacBook Pro that still runs as fast as the day I bought it. The first thing I did when I got it was to create a modestly-sized "backup partition" on the internal drive, and place a clean version of the OS onto it. With that, I have an "alternate boot partition" available to me, so that I may "switch boot" when needed to perform maintenance on my "primary partition". You'd be amazed what a defrag and optimization will do for the old drive...
  7. ritzer3 thread starter macrumors newbie

    Jan 3, 2013
    Advices taken :) I can definately scrape up that much once my student loan comes in, just i have become pretty impatient with my laptop, but it is still usable, so i guess i will have to keep my fingers crossed that it doesnt catch fire or get nicked whilst I wait to buy an external HD and do a backup :D

    Thanks alot for the guidance, I shall follow your advice once I've bought a HD and report back :)

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