AmgadHS

How to Create DMG File in Mac OS X

Ever since I started using a Mac at home, I found DMG files very useful. DMG files are disk images that can be easily mounted in Finder and accessed just like any other disk. I mainly use them for files and folders I do not use frequently. But I also use them for files I want to protect with a password.

Creating a DMG file is very easy, just run the Disk Utility program that comes with OS X which can be found by going to the Applications folder and then to the Utilities folder. Click the ‘New Image’ toolbar button to get the dialog box displayed above. Here are the descriptions of the fields that need to be set:

• Save As: Type here the name of the file, i.e. enter disk01 to get disk01.dmg.
• Where: Where will the file be created. After the file is created, it can be moved to any other location.
• Volume Name: This is the name that will appear in Finder when the file is mounted.
• Volume Size: DMG files are disk images, so the size entered here will be fixed, even if it is empty. And the data inside it can not exceed this limit.
• Encryption: This list has three options: none, 128 bit, and 256 bit. If 128 bit or 265 bit is selected you will be asked to enter the password to be used to access the DMG file.
• Image Format: This should be left at ‘read/write disk image’ when creating the file, to be able to copy the files to it. Later on it could be made read only.

When finished setting the fields above click the ‘Create’ button. To change the DMG file’s Image Format and Encryption settings or add compression after the file is created, select it and click the ‘Convert’ toolbar button.

Now that the file is created, double clicking it in finder will mount, and it will be displayed in the left panel.