How to restore OS X without the disc

By: agreimann
February 1, 2011

Recently, I've written a few postings on how to do things that a new Apple migrator struggles with, such as answering the fundamental questions of whether older Apples can run Windows, and how to find certain keys on Apple notebooks they're accustomed to from their laptop PCs. If you'd like to learn more in these areas, please, feel free to read these. :)

In this how-to, I'd like to cover a more interesting, useful topic that even experienced Apple users can have trouble with, which is how to restore an Apple desktop or notebook without having the original CD on hand.

Before continuing onward, I need to state that this should only be used for your own software. It should NEVER be used to copy anything that is not others' or yours (as that is piracy), but to simply restore your computer, and also I'll cover how to archive and restore it later. This article is going to be VERY long--prepare to read a lot.

Part 1: Make a bootable OS X disk

This whole process is completely free, and does not require any special software, provided that your computer is running OS X 10.3 or later. With that in mind, let's get started on a very LONG task:

1) To start, open Disk Utility. There are two ways to do this. The first is to switch to the Finder from the Dock, find the menubar, open the Go menu, click Utilities, and open Disk Utility. The second, for OS X 10.4 "Tiger" and later, is to use Spotlight by pressing Cmd+Space, and to type "disk util". You can then use the arrow keys (if you need to), and press return. Either way, Disk Utility should now be open for you. :)

2) In the Disk Utility window, click the partition in the left pane that is your startup volume on your hard disk, or the one you want to back up. Even if you think your permissions are fine, it is **strongly** recommended to click Repair Disk Permissions and let the computer repair any permissions errors. This will save a heap of trouble with booting the removable disk. :)

3) Now, click the *device*, not partition, that you want to restore to. I recommend at least an 8 GB removable drive, if not a 16 GB for today's computers. In the case of an empty iPod (nothing on it or everything backed up and iTunes closed), click the device, for instance, that says "7.3 GB Apple iPod Media" above the indented partitions underneath it. If you're using a flash drive, it will say something different, but in the same layout described.

4) Click the Erase tablet to open the Erase pane. In the Volume Format drop-down list, select "Mac OS Extended (Journaled) and name it "MYDISK" or something similar. Unless you really need it, uncheck "Install Mac OS 9 Disk Driver". Click the Erase button. In the sheet that rolls up, click Erase again.

5) Now, switch back to the Finder and in the other device that you're using, (assuming you have two flash drives), take the Applications folder, and start dragging it to that device while holding down the Option key. Drop it on the drive. If some apps need special permissions, note and skip them. When done, open the Applications folder, and delete everything backed up EXCEPT the ones that said they didn't copy completely due to permissions. Also, backup your home folder separately to DVDs, CD writables, or another large flash drive. This will significantly lower your disk usage size--especially if you have a bunch of apps--most basic users won't notice much of a difference, though.

6) On the Desktop, find the disk you are using as the destination disk. In my case, it is Restore Disk. Go ahead and click it once, and in the menubar, open the File menu. Click Get Info. (You can also press Cmd+I or Ctrl-click and click Get Info.) Under the "Ownership & Permissions" subpane, uncheck "Ignore ownership on this volume." Close the window. You *can* do this in the Terminal, but because this is geared toward even the new Mac user, it's not included. :)

Switch back to Disk Utility in the Dock. Now that the destination and source destinations have been set up, click the device that is your hard drive from the side pane. In other words, the part that says "160.0 GB DRIVE INFO" (where DRIVE INFO is the actual make and model) above the partitions indented below it.

8) Click the Restore tablet to open the Restore pane. From the side pane, drag the partition underneath the device you clicked that you wish to back up to the "Source" box, such as "Macintosh HD" or "Hard Disk". Then, drag the removable disk partition (in my case, MYDISK) to the Destination box. Make sure that "Erase Destination" is unchecked, and "Skip Checksum" is checked.

Note it is *critical* that the data being transferred is SMALLER than the size of the destination disk if you want everything to fit. That's why I recommended taking the contents of your home folder and Applications out.

9) Click Restore, and if a sheet rolls down, click Restore again, and wait. Depending on the speed of your FireWire or USB port, this could take anywhere from an hour to HOURS of time.

10) Once everything is done, click the device that you just restored to. You can click the partition, but it's recommended to repair permissions from the root of the drive you restored to, which I'll get to in a minute. Click the First Aid tablet to switch to the First Aid pane, and click Repair Disk Permissions. Wait a while. It's worth it, for the next step.

11) Now that we are for the most part, all done, quit Disk Utility and switch to the Finder. Select the disk you restored to by clicking it once, and Get Info. Hopefully, I described three ways of doing this before. :) Look in the Ownership & Permissions subpane, and see if under Advanced or another subpane, system and admin own the disk now. If so, success. The disk is ready to boot at last.

12) Go to the menubar, open the Apple menu, click System Preferences... and under System, click Startup Disk. Click the lock icon to "authenticate", and find your disk. It should appear. Click Restart, and Restart again, once you've selected it. You've made a successful backup. Now, if it doesn't show up, there might still be hope. You can restart, hold down the Option key right after the chime, and find your disk there. If it doesn't show up here, then your computer is too old to support USB booting, and you do need either a CD/DVD or a FireWire drive.

Otherwise, congratulations! You successfully made a bootable OS X disk!

That's the end of Part 1. Now, I'm going to go a little deeper than Part 1. What if you want to keep an archive (or snapshot) of your system that's bootable, you want to free up your disk, and you don't have a CD? That is no problem, and is completely free like the method above, as we will see. (But, hopefully, by then, you'll have retrieved your long-lost restore disc or have bought a new one.) :)

Part 2: Convert backup to disk image & restore

Now that you have successfully made a long and tedious backup of your OS X copy that is bootable, you can actually free up that flash drive, and your computer's hard drive at ease as well. I'll cover the three main operating systems that people use here, and will explain how to do this on each.

Skip to the OS applicable to you, that you run. :) I'll discuss OS X, Windows, and Linux in that layout, (if you want to know where to find each). Then, when you're done reading your OS section, check out the final notes for how to restore your computer when it crashes.


If you have a spare OS X computer that is sitting around, that has enough disk space to hold the size of the disk you just backed up, then great! You can work with OS X, again, from that machine. The steps are actually simple.

a) If iTunes starts bouncing in the Dock, or other apps start to "automatically" open, close them by control or right-clicking them, and pressing Quit. Hold down Option with the docklet open if necessary to change "Quit" to "Force Quit" if the app refuses to quit normally.

b) Switch to the Finder, find the menubar at the top of the screen, open the Go menu, and click Utilities. Find and open Terminal.

c) Now that you've got a black-and-white window with text in front of you, don't get scared. Only about three commands will get entered here. :) From now on, I'll put code in quotes. Do NOT include the quotes unless specified when typing them in. Start by typing "diskutil list" and press return. You can guess your drive by label or size, such as if it is 7.3 GB or labeled "MYDISK"

d) I'll assume my disk is /dev/disk1 in my case. So, I would type "diskutil unmountDisk /dev/disk1" and press return. Replace 1 with your disk number.

e) Now, for instance, to copy the data I copied in Part 1 to my home folder, and my shortname is andrew, I'd type in "sudo dd if=/dev/disk1 of=/Users/andrew/my_osx_backup".

Note that my_osx_backup could be named what you want--but don't get *too* creative (spaces, weird characters, etc.) unless you've worked with Unix-like systems. Also, to find your shortname if you don't know it, type whoami, and OS X will tell you. Plug in your shortname into the path like I did for "andrew".

f) Open Disk Utility (switch to Finder -> Go -> Utilities -> Disk Utility) and click the disk in the left pane. In the toolbar, click Eject. Voila! You're done.

Any time you want to copy all your "bootable OS X" work back to the drive (but note this will instantly erase the drive once you execute it), type in the inverse of your original command. In my case, I'd type "sudo dd if=/Users/andrew/my_osx_backup of=/dev/disk1" to put the backup back on.


If you have a spare Windows PC, we can use it, too.

a) Since Windows does not have the dd command included with it, we'll need to download it. Go to and grab a copy of dd. Unzip the folder if necessary.

b) Press the Windows logo key + R on your keyboard, and without quotes, type "%windir%\system32". Drag the contents of the dd folder to the system32 folder, if you will. In other words, have both folders open, and drag what's in the dd one over to the system32 folder. If you are on Vista or 7 and have UAC on, you are copying the files, so give the computer your password, and click Continue. Close both folders when finished.

(The reason that you need to move it is so you can use it as a natural command, like you would "dir" or another Windows command.)

c) This varies by version (please read below):

- On Windows XP, if you are logged on as an administrator, press the Windows logo key + R, and type "cmd". Don't include quotes.
- On Windows Vista and 7, open the Start menu. Type command, and right-click Command Prompt in the results. Click "Run as Administrator", give it your password, and click Continue if UAC is on.

d) Type (using no quotes) "dd --list --filter=removable" and press Enter. From the drives that appear, choose the one that best matches your size or label, such as MYDISK, for instance, or 7.3 GB.

e) In my case, the disk would be labeled "\\?\Device\Harddisk1\Partition0" and my username was "Andrew", I would type in the next command, depending on my Windows version:

- On Windows Vista and 7, I'd type "dd if=\\?\Device\Harddisk1\Partition0 of=Users/Andrew/my_osx_backup" (no quotes)
- On Windows XP, I'd type "dd if=\\?\Device\Harddisk1\Partition0 of=my_osx_backup" (no quotes) I'm not sure if Documents and Settings will be recognized by dd, so this should copy the image right to C:\.

Any time you want to restore your "bootable OS X" work back (note this will instantly format the disk once you execute it), type in the inverse of your original command. On a newer version of Windows, for instance, I'd type "dd if=Users/Andrew/my_osx_backup of=\\?\Device\Harddisk1\Partition0" to put the backup back on.


Last but not least, we have my second favorite operating system--Linux. This is actually going to be the simplest of the operating systems to cover, outside of OS X. Like OS X, Linux includes dd. Whenever quotes are included around commands, unless specified, DO NOT use quotes.

a) Press Alt+F2 or Meta+F2, and type in "gnome-terminal", "konsole", "xterm", or whatever shell for whatever environment you are using to open the shell. :)

b) In the new shell window that popped up, type in "sudo -s" to gain administrative privileges, type your password (no characters will show), and press Enter.

c) Type in parted -l and note your drive that you are using. In my case, it will look close to 7.3 GB and might be labeled MYDISK. Look for something close to your drive.

d) If my shortname is "andrew", similar to OS X, and my device was called /dev/sdb, I'd type in "dd if=/dev/sdb of=/home/andrew/my_osx_backup" and press enter. Obviously, substitute /dev/sdb and andrew for your shortname and device.

Note your filename can be different than my_osx_backup, but don't get *too* creative in using spaces, and special characters, unless you know what you're doing on a Unix-like system.

(Hint: To find your shortname, similar to OS X, type in "whoami".)

To restore your work to your disk instantly, (note it will erase all old data off the disk after you execute dd), type the inverse of the command, where I'm plugging in the same info as before: "dd if=/home/andrew/my_osx_backup of=/dev/sdb".

A few last notes:

If your Apple can't boot, and you've made your backup as described in parts 1 and 2, you can still restore your computer without your OS X disc. Download a PowerPC version of Ubuntu, and burn the .iso to disc with ImgBurn for Windows, Disk Utility on OS X, or the Nautilus file manager in Linux. Run the live environment (do not install it!), plug in the removable disk, press Alt+F2, type gnome-terminal, press return, and finally, do something a little bit different than in previous steps.

1) As usual, type in sudo -s, type in your password, and press return.
2) Type in parted -l, locate your disks, and note both your hard disk and removable disk names.
3) For the next command, assuming the removable disk is /dev/sda and the hard disk is /dev/hda, with no quotes, type "dd if=/dev/sda of=/dev/hda". Press return, type reboot, and press return again. You're done!

That is **finally** it!

Now you know how to backup, convert, save, and restore the contents of your hard disk using completely free tools efficiently and quickly. Now you can boot your computer without having your disc, but hopefully, you won't have it lost too long. :)

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