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Both command-line and screen-oriented pointers appreciated!


I verified the disk utility, hdiutil, and dd methods. dd seems the fastest, 30 minutes on my macbook pro vs. 40 minutes for hdiutil. I was able to simplify dd to use just if= and of=

For the DVD, I used /dev/disk2. I verified this with diskutil list and unmounted it first.

$ sudo umount /dev/disk2
$ dd if=/dev/disk2 of=mydisk.iso
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migrated from serverfault.com Dec 21 '09 at 7:59

This question came from our site for system and network administrators.

Yeah dd is the fastest, it is the disk druid, after all! :) –  msanford Nov 30 '10 at 21:46
why did you unmount disk2? I thought you need to leave the DVD drive mounted, so you can read the data from it? –  Pure.Krome Jan 11 '11 at 22:55
@Pure.Krome, for this purpose, /dev/disk2 is a file of several GB length. The directory structure is embedded in those bytes. IIRC, I had to umount in order to read /dev/disk2. –  Mark Harrison Jan 12 '11 at 21:15
I had to use sudo diskutil unmount /dev/disk2 not sudo umount /dev/disk2 –  nikans Sep 11 at 21:44
In my case I had to do the following (OSX 10.9.5): sudo umount /dev/disk3s0 ; sudo dd if=/dev/disk3s0 of=mydisk.iso –  Oisin Oct 18 at 18:12

9 Answers 9

up vote 113 down vote accepted

There are generally three ways to create a disk image on an OS X box:

  1. Disk Utility - The on-screen prompts will guide you, but it will by default create a .dmg, which is an OS X-specific file format. Disk Utility will also create an ISO (.cdr extension) if you select the "CD/DVD Master" option before creation the image. Rename the extension (to .iso) after creation if needed.

  2. Roxio Toast - The de facto third-party standard in creating optical media on Mac OS for over a decade, it will create almost any CD or DVD format you want.

  3. The hdutil command-line utility, which will, in fact, create every format that Toast supports, for free, though it is far less pretty. If you want to create an ISO with this tool, use hdiutil makehybrid -iso -joliet -o Image.iso /input_path

There is a fourth, extremely direct command-line way using dd that sysadmins might know: dd if=/dev/disk1 of=Image.iso

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Open /Application/Utilities/Terminal.app/

sudo diskutil unmount /dev/disk1
dd if=/dev/disk1 of=~/myCD.iso bs=2048 conv=sync,notrunc

That should do it!

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Way to beat me to it ;) This is the most elegant, lowest-overhead solution. See my others below. –  msanford Jun 29 '09 at 5:10
BTW, does cat /dev/disk2 > ~/dvd.iso work here? –  boehj May 31 '11 at 22:50
This gives me a resource busy error, although no finder window is open to the DVD and no disk utility or any other app that I can find is using the DVD? –  Ali Jan 25 '13 at 16:53
for this solution to work, you need to know the name of the device, which you can find out by typing "df" in a terminal, and looking for your CD/DVD in the list. Then choose the device name that shows on the far left. Then unmount the device using "sudo umount /dev/YOUR_DEVICE_NAME", then use the dd copy approach detailed above to do the copy. –  Brad Parks Jul 24 '13 at 17:44
To fix the "Resource busy" error, please use Disk Utility to "Unmount" the disk and everything below it. –  Ketan Dec 7 '13 at 20:55

Actually Disk Utility will create an ISO (.cdr extension). Just ensure you select the "CD/DVD Master" option before creation the image.

That file can then be used like any other ISO file only requiring a rename for certain dumb Windows apps that baulk at the .cdr extension.

Been using this method for ages with no problems.

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I have created a .cdr, it has been automatically mounted to Mac OS. I copied there all files from bootable USB flash drive. Dismounted. Trying to mount to Virtual Box: Could not get the storage format of the medium '/Users/nakilon/_/mrddr_flash_diskutil_dvdmaster.iso' (VERR_NOT_SUPPORTED). –  Nakilon Aug 30 at 9:00

As mentioned in other answers you can use Disk Utility or dd to create an ISO image of the original disc. But if the disc is copy protected, it contains decryption keys in the lead-in area of the disc which cannot be read directly, and are not part of the ISO image. So if you burn a new disc with this image it will not play on a standard DVD player. Nevertheless, you can play it using a program like VLC which doesn't need the keys, since it is able to circumvent the encryption.

If you want a program that will copy the disc to the hard drive and also remove the copy protection so that you can burn it to a new unprotected disc, MacTheRipper will do that, but it looks like it hasn't been updated in a while. (Only a PowerPC version is listed.)

For storing on your hard drive you might find it more useful to transcode the content to unencrypted H.264 using Handbrake. This will save you a lot of disk space compared to storing the MPEG-2 content that is used on DVD-Video discs. However, it will not preserve the DVD menus, and if you want to burn a DVD that you can play on a standard DVD player then you would have to convert it back to MPEG-2.

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After looking into dd command line tool...

I found you can also create a disk image using disk utility.

Just create a new image and select “DVD/CD Master”. - Apple adds the extension .cdr but you can rename the file to end in .iso and it will work as a standard ISO.

Anyone know how this effects any drm protection on disks?

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Assuming that the Disk Utility is just using dd, it's no different - the iso is a bit for bit copy of the disk. –  Rich Bradshaw Aug 30 '09 at 15:49
Rich is right, the iso is an identical copy of the DVD. –  alex Sep 1 '09 at 7:40
Not if it is copy protected. See my answer for details. –  mark4o Sep 1 '09 at 17:50

You can use the dd command line tool. Make sure you unmount the drive first though.

dd if=/dev/dvd of=dvd.iso

This will make a bit-for-bit copy of the DVD.

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It's not /dev/dvd! Go to Disk Utility, find the disk you want and open the info dialog, it says the proper /dev/* there –  Isaac Waller Aug 30 '09 at 16:59
its an example, you would obviously replace it with your DVD drive which would be something like /dev/hdb1 or /dev/scd0. –  John T Aug 30 '09 at 17:07
Most likely /dev/disk1 or disk2 on Mac OS X. –  mark4o Aug 30 '09 at 22:06
mark4o is probably correct. I'm a UNIX guy if you couldn't tell, Mac just shares the majority of command-line tools with UNIX which helps me answer more Mac questions. –  John T Aug 31 '09 at 1:50

Don't forget asr, the Apple Software Restore command-line utility: it can operate like a raw copy program like dd, but it has more bells and whistles. Not least, it will work directly with volume pathnames, as dd won't.

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I've been looking for a way to do this for a while (obviously didn't look too hard) and this works really well for me. My goal is to get all my disks "backed up" and encoded so that my AppleTV can play them from my NAS box with an AC3 soundtrack.

I have a Mac Pro with 2 DVD drives in it.

Opening 2 terminal windows allows me to make 2 ISO's at the same time, by specifying the different drive in each window. The hard disk is faster than the two DVD drives, so there doesn't appear to be a bottleneck, even when they are both being written to the same disk or folder.

The crucial piece, and if like me you just want the main feature, not the menus etc...is to use Handbrake as mentioned, but if you have VLC sitting in your Applications folder, the latest version of Handbrake uses VLC on-the-fly to bypass the disk protection.

My solution is now to RIP 2 disks at once and when they are done, queue them up in Handbrake to change them to my preferred video profile. I reckon I will be saving hours and hours by the time I have been through my collection!

Thanks again for the inspiration found here!

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I'm normally a command-line person myself, and the built-in Disk Utility works pretty well also, but I recently stumbled across another good and free alternative called Burn. Among its many features is the ability to make disc images:

  1. Download Burn, then extract and open it
  2. Put your disc in
  3. Open the Copy tab
  4. Click Scan...
  5. Select the disc and click Choose
  6. Click Save..., choose a name and location, and click Save
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Wow. I already had burn, but I didn't know it could do this! It works very well. +1 –  cullub Dec 19 at 17:32

protected by nhinkle Apr 26 '11 at 8:07


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