I have seen lots of users looking for a macOS iso file or macOS dmg file, I wonder what’s the difference between them? Are they used on different hard drives or for any other reason? How can I create a macOS iso file or macOS dmg file on my own as a rookie to the Mac operating system?
An ISO is a bit-for-bit image of an ISO-9660 (CD-ROM) disk. You can write it directly to a CD and use it directly. A DMG is typically the Universal Disk Image format, kind of like an image of a hard disk partition. They have different layouts but are similar in that they hold an image of a file system with files accessible after mounting by the operating system.
However, they are different because DMG files only work on Mac, while ISO works on Mac, Windows, and even Linux systems.
What is a macOS iso file?
A macOS ISO file (.iso) is a disk image file for macOS, typically used for installing macOS on virtual machines like VMware or VirtualBox, creating bootable installers, or for other installation methods beyond the standard upgrade process provided by Apple through the Mac App Store or Software Updates.
If you have a macOS ISO file, you can create a new virtual machine in VMware or VirtualBox, mount the macOS ISO as the virtual disc drive, and then install macOS on that virtual machine, effectively running a macOS within your actual computer, regardless of whether your actual computer is running Windows, Linux, or another operating system.
This allows users to test, develop, and run macOS and applications in isolated environments without needing to modify their actual computers, which can be especially useful for developers, testers, and IT professionals.
What is a macOS DMG file?
DMG is a file format mainly used to store and distribute compressed software installers for Mac devices.
Most of the time, you only see the DMG files when you download a program or software from the Internet. After downloading, it mounts as a disk on your Mac. You can copy the app from the DMG file to your Mac to finish installing.
Therefore, a DMG file is always regarded as a virtual disk drive. Every time you open a DMG file, it will be auto-mounted and appear in Finder under the Locations tab, just like other physical disks. In addition, it will also show up in Disk Utility.
How to create a macOS ISO file?
It’s not as complicated as you imagine to create a macOS ISO file. Here is how to create a macOS ISO file:
- Step 1: Download the macOS Sonoma full installer
- Step 2: Create an empty ISO disk image in Terminal
- Step 3: Make the macOS Sonoma installer
- Step 4: Unmount the macOS Sonoma disk image and convert it into the .iso format
If you want detailed steps on making the macOS ISO file of each released Mac operating system, you can click the following links:
DMG to ISO convert
Since ISO is compatible with Windows and macOS, yet DMG only opens to macOS, users demand that DMG be converted to ISO. Converting DMG to ISO on Windows is easy with the assistance of dmg2img, a perfect tool for DMG to ISO conversion.
You can download this software to complete the conversion task on your PC.
If you want to convert a DMG to ISO on a Mac, all you need is the Disk Utility toolkit.
How to convert a dmg to ISO on Mac via Disk Utility:
Step 1: Open Disk Utility
Insert the CD / DVD that contains the file you want to convert. Open “Finder” and by clicking on “Go,” select the “Utilities” option then “Disk Utility.”
Step 2: Convert the DMG file
When Disk Utility opens, check the name of the disk we want to insert in the highlighted region. Click the “Images icon” in the toolbar. When prompted, find the ISO file you want to convert, click on “select,” and click the “Convert” button.
Step 3: Name the file
Give the new file a name and navigate to the desktop to save it there. Make sure to give it a name with the extension .dmg. Select the compressed image format from the drop-down list and click “Save.”
Step 4: Confirm conversion.
A dialog will open, whereby you should click on Image Format, choose DVD/CD master and then select Save for DMG to ISO conversion confirmation.