How To Install OS From DMG?

In a quandry. I have this 5.1 Gb disc image of an OS I want to install on my PowerBook. But, can’t get there from here.

Obviously can’t create a DVD: Too big of a bucket of files & don’t have dual layer DVD writer.
Can’t restart and boot of a DMG alone.

So, how do I do this? Any smarties out there wanna show up the old guy?

[EDIT: nevermind… see comments below]

Explore posts in the same categories: Apple, leopard, mac, MacOSX, Powerbook, Tiger OSX

15 Comments on “How To Install OS From DMG?”

  1. gwhiz Says:

    God how I love the internet! Google supplied me a trace on my answer.

    With your DMG and Disk Utility + a spare destination partition you’re willing to blank out you have no need for a dual layer DVD writer. I’ll post more on the process later. Many an Apple Developer is going to want to know this trick.

  2. andrewlorien Says:

    And the answer, since this post was the closest i got…

    open “disk utility” (from applications | utilities)
    click “scan image for restore” (from the images menu)
    select your dmg file. wait.
    click “restore” at the top of the main window
    drag the image (the disk icon under the dmg file at the bottom of the left hand pane) to the “source” field, and your disk (the icon for your firewire disk or whatever, at the top of the left hand pane) to the “destination” field.
    wait again.

    restart the computer. hold down the “alt” key. the drive should appear along with your normal hard drive as a startup disk.

    WARNING: most macs can’t boot from a usb disk – many can boot from firewire and scsi, all can boot from an internal drive or a cd/dvd.

    that’s what i learnt today… thanks for the pointer gwhiz.

  3. gwhiz Says:

    Thanks for that Andrew. Appreciate yet another good bit of advice from the experienced out there!

  4. hiohokaybye Says:

    i tried it and it says i cand do it cuz i dont have the permission…. help me

  5. Jan Toonen Says:

    Please note that intel machines do not boot from a standard (old) partition scheme.
    You’ll have to repartition the firewire disc. Before one recovers the volume from the dmg disk

  6. josh Says:

    ok i need a looooooooooooot of help. lol first off i dont know how to partition my Western Digital 500 GB fire wire external. can anyone help??

  7. Hi, in response to not being able to boot from external USB.
    you can boot, but you need to change the partition to guid-labeled.
    you can find this in Disk Utility on the external HD and then on partitions click options.
    you’ll find it right there.. that way you can use the external USB HD as a startupdisc


    mine says “cannot scan boot disk not recognized”

  9. cbmtrx Says:

    …presumably one doesn’t need to partition an external firewire drive in order to boot from that drive for an OS X installation? I’ll likely just erase that drive once the install is done…

    Jan Toonen–regarding the permissions thing: when you click on the drive in the left window pane (before restore) it will display, among other things, “Permissions enabled”. If this is no, I believe that you have to first erase/reformat the drive (Mac journaled) and then click on “Repair disk permissions”. (I’ve seen the suggestion that you might have to use Terminal for this if the repair permissions doesn’t work, but that’s a whole other story!).

  10. KAGE Says:

    Hi, my name’s Kage from Hong Kong and I’ve got a trouble problem on updating to Leopard.
    My machine is PowerBook G4 (1Ghz processor, 1GB ram, OS 10.2) and I wanna upgrade to Leopard. My friend burned a osx-leopard105.dmg dual layer DVD to me, so I’m trying to install to my machine. However, the OS tells me to restart the computer to continue the installation, once I restart, nothing is happening…I’ve tab “C” when the OS restarted, but nothing question more, how come my “Disk Utility” got no “Scan image to restore”? Actually, I didn’t see any “Restore” from the DU…
    Please help me to solve these problems, thanks bros

  11. not that it matters Says:


    You’re likely having a problem because of the recordable dual layer media. Plenty of older dvd drives work great with a real (pressed) leopard DL disc, but not with recordable DL discs. PITA.

  12. […] was trying to install mac-osx 10.5 leopard and I went to this site How To Install OS From DMG? gWHIZ I followed the 2nd guys comment and when I restart, my mac is just stuck on the loading screen with […]

  13. pyrokarma Says:

    Hello there

    So, I have a PowerBook G4, and a Western Digital HD. I have been following all the outlined steps, and it is not working for me. I have a leopard .dmg, and when I put it on the external HD, all it does is act like the disk (shows the 4 folders), but it will not let me boot into it.

    Please help

  14. very goodddddddddddddddddddddddd

  15. Karen Howard Says:

    In the system Preferences locate startup disk and tell it to start to the image that you just made hope this works it worked for me

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