How to Create a Mac OS El Capitan ISO for VirtualBox

Looking around, I've found a few pointers on how to convert an installation file into something that can be used to boot a virtual machine. Depending on the purpose of the ISO file, if it's to reinstall a computer, it might be more useful to use a Bootable USB drive instead. For this, you can check out the instructions on how to create a bootable installation for OS X Mavericks 10.9 and above.

Alternatively, I've mostly used the information found on the InsanelyMac site, combined with the tip on creating a Recovery Partition from the Apple Support Communities. The process involves getting an ESD image, rebuilding it to include information that is now packaged as symlinks, and then extracting it as an ISO file. However, Apple has changed the format of the ESD image, making it no longer bootable. This means that the method above won't work on Mavericks.

Fortunately, you can use this process on any version of OS X from 10.6.8 (Snow Leopard) onwards. This allows you to use an old image to obtain a new one, for example, if you have access to a different OS version than Mavericks. To do this, you'll need to use an external hard drive or thumb drive that is formatted in ExFAT format.

To start the process, open up Disk Utility and select Images > Convert from the menu bar. Point it to your ESD image file, which can be found on the Apple support site. This will create a dmg file that is essentially an ISO file in a slightly different format.

Next, navigate to the folder where the dmg file was saved and open the Contents > Shared Support folder. You'll see a disk image file called InstallESD.dmg. Right-click (or Control+click) the installer and choose Show Package Contents from the resulting contextual menu. This will reveal the Installer app, which should be located in your main Applications folder or dock.

Once you have downloaded the installer and it's available in your dock, you can simply pick it apart to access the image file that is inside it. Unfortunately, there is no legitimate way to obtain this file without having access to a Mac and a licensed copy of the

Mac os el capitan iso for virtualbox