One step ISO creation from folders in OS X


Icons from the Tango Desktop Project

Here’s a great little trick I discovered this afternoon. Previously, if I wanted to create an ISO image to either burn or mount in a VM, I’d do this:

  1. Create “CD/DVD master” from a folder using hdiutil or Disk
  2. Convert to a “hybrid image”
  3. Rename the file from *cdr to *iso

I’m not sure how long we’ve been able to do this, but you can specify it with just one command now, using the “UNIV” flag. For example:

% hdiutil create \
    -volname MSDOS6 \
    -srcfolder EN_MSDOS60 \
    -ov -format UNIV \
% mv image.dmg image.iso

Okay I cheated, there are two commands there. Still, now I have a way to create an ISO image I can mount in virtual machines (or burn) without a conversion step.

If you’ve found that useful, feel free to bankroll me an upgrade to the latest VMware Fusion on the Buy me a Coffee page. Hey, one can dream, right? ^_^

The rather retro set of icons above are from the Tango Desktop Project, originally assembled for this FreeBSD post in 2009.

Update: The other way

I had a few people ask me what I meant by “convert to a hybrid image” in my original procedure above. In a nutshell, if you’re created a “CD/DVD master image” and have a something.cdr file, you can convert it by doing this:

% hdiutil makehybrid -iso -joliet -o image.iso image.cdr

Creating a hybrid image from the start negates this step, though perhaps there are circumstances where this approach may be preferable. Happy imaging!

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Ruben Schade is a technical writer and IaaS engineer in Sydney, Australia who refers to himself in the third person in bios. Wait, not BIOS… my brain should be EFI by now.

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