One of the ways you can store or group multiple files together on a Mac is to create a disk image. Basically, a disk image is a file that has properties and is handled as if it were a separate disk drive, allowing you to compress data or encrypt it with a password. DMG files come with a number of options related to size management and encryption in order to protect your data by keeping it safe. While there are several applications that can do this for you, it's best to create an image file completely manually.
Steps
Method 1 of 2: Create a DMG File Manually
Step 1. Create a new folder to place the desired files
Move the files you want to insert into the disc image into the created folder. This step is intended to make it easier to access during the disk image creation process.
Step 2. Select the folder in question with the right mouse button (or hold down the "Ctrl" key while clicking), then choose "Get information" from the context menu that appeared
Make a note of the size of the files it contains to know how large the resulting DMG file will be.
Step 3. Launch the "Disk Utility" application
Go to the "Applications" folder, then choose the "Utilities" item. The "Disk Utility" application will appear in the appropriate drop-down menu.
Step 4. Select the "New Image" icon to create a new disk image
Alternatively, you can access the "File" menu, choose the "New" item and finally select the "Blank disk image" option. Enter the name you want to assign to the image, then choose the size of the DMG file that will be created. It must be large enough to accommodate the files you have selected. From this window you also have the option to encrypt the folder. If you don't need to encrypt the file, choose the "None" option from the "Encryption" drop-down menu.
Step 5. Press the "Create" button
This will create a DMG file according to the specified specifications. You should see it immediately appear on the desktop or inside the Finder window sidebar. At the end of the operation you can close the "Disk Utility" window.
Step 6. Insert the data into the newly created disk image
All you have to do is select the desired files and drag them into the DMG file.
Method 2 of 2: Download an Application for Automatic Creation of a DMG File
Step 1. Find the application that meets your needs
Creating a DMG file manually is a very simple process, but if you want to consider using an application that automates this task, you can choose to download one. Search for these types of programs, then read the reviews of users who have already used them to be able to compare them and choose the one that best suits your needs. There are some very good options that can further simplify the process of creating a DMG file; the most famous are iDMG and DropDMG. In this article we take DropDMG as a reference, but the other application works in a very similar way.
Step 2. Download and launch the app in question
Drag the downloaded file into the "Applications" folder, then double-click it to select it. Once the program opens, select the "Eject" icon next to the application.
Step 3. Restart your computer
This way the new changes to the system will be applied.
Step 4. Restart the DropDMG app
Once the computer startup procedure is complete, you should be able to access the application under consideration.
Step 5. Create a DMG file
The DropDMG program automatically converts the selected files into disk images. All you have to do is drag and drop the desired files into the app window, DropDMG will do the rest of the work for you.
Advice
- After adding the desired files to the image, you can unmount and press the "Convert" button on the toolbar. In this way you will have the possibility to compress the image file, to make it available for reading only or to encrypt it to increase the security of the information it contains.
- To create an image starting from a folder, drag it to the Disk Utility icon or access the "File" menu of the Disk Utility window, then choose the "New image" option and finally select the "Image from folder" item.
- DMG archives are a quick and easy way to send files from a Mac to any other OS X system. Any Mac can mount and access the information contained in a disk image.
- After selecting a DMG file with a double click of the mouse, it will be "mounted" directly on the desktop (in other words it will be made accessible directly from the Mac desktop). This is the only way to be able to access or modify the content of this type of file.
- If you are using the manual method, you have the option to encrypt the disk image using a login password; in this way the information will be safe. To do this, select the "AES-128" option from the "Encryption" drop-down menu. After hitting the "Create" button, you will be asked to provide the password to protect your files. By adding the password to the "Keychain" linked to your user account, you can access the DMG file without having to provide the access password, as long as you have logged in with your user account.
