File system formats available in Disk Utility on Mac. Disk Utility on Mac supports several file system formats: Apple File System (APFS): The file system used by macOS 10.13 or later. Mac OS Extended: The file system used by macOS 10.12 or earlier. MS-DOS (FAT) and ExFAT: File systems that are compatible with Windows. Open Disk Utility for me. Back Up Your Files! Okay, so you may have a lot of files that you want to get rid of, but you definitely.
Disk Utility User Guide
You can use Disk Utility to create a disk image, which is a file that contains other files and folders.
Note: You can burn information to a CD or DVD using the Burn command in the Finder. See Burn CDs and DVDs.
Create a blank disk image for storage
You can create an empty disk image, add data to it, then use it to create disks, CDs, or DVDs.
In the Disk Utility app on your Mac, choose File > New Image > Blank Image.
Enter a filename for the disk image, add tags if necessary, then choose where to save it.
This is the name that appears in the Finder, where you save the disk image file before opening it.
In the Name field, enter the name for the disk image.
This is the name that appears on your desktop and in the Finder sidebar, after you open the disk image.
In the Size field, enter a size for the disk image.
Click the Format pop-up menu, then choose the format for the disk:
If the disk image will be used with a Mac that has a solid state drive (SSD) and uses macOS 10.13 or later, choose APFS or APFS (Case-sensitive).
If the disk image will be used with a Mac with macOS 10.12 or earlier, choose Mac OS Extended (Journaled) or Mac OS Extended (Case-sensitive, Journaled).
If the disk image will be used with a Mac or Windows computer and is 32 GB or less, choose MS-DOS (FAT); if it’s over 32 GB, choose ExFAT.
To encrypt the disk image, click the Encryption pop-up menu, then choose an encryption option.
Click the Partitions pop-up menu, then choose a partition layout.
Click the Image Format pop-up menu, then choose an option:
Sparse bundle disk image: Same as a sparse disk image (below), but the directory data for the image is stored differently. Uses the .sparsebundle file extension.
Sparse disk image: Creates an expandable file that shrinks and grows as needed. No additional space is used. Uses the .sparseimage file extension.
Read/write disk image: Allows you to add files to the disk image after it’s created. Uses the .dmg file extension.
DVD/CD master: Changes the size of the image to 177 MB (CD 8 cm). Uses the .cdr file extension.
Click Save, then click Done.
Disk Utility creates the disk image file where you saved it in the Finder and mounts its disk icon on your desktop and in the Finder sidebar.
In the Finder, copy your files to the mounted disk image, then eject it.
Restore the disk image to a disk.
For more information about disk image types, see the manual (man) page for hdiutil.
Create a disk image from a disk or connected device
You can create a disk image that includes the data and free space on a physical disk or connected device, such as a USB device. For example, if a USB device or volume is 80 GB with 10 GB of data, the disk image will be 80 GB in size and include data and free space. You can then restore that disk image to another volume.
In the Disk Utility app on your Mac, select a disk, volume, or connected device in the sidebar.
Choose File > New Image, then choose “Image from [device name].”
Enter a filename for the disk image, add tags if necessary, then choose where to save it.
This is the name that appears in the Finder, where you save the disk image file before opening it.
Click the Format pop-up menu, then choose an option:
Read-only: The disk image can’t be written to, and is quicker to create and open.
Compressed: Compresses data, so the disk image is smaller than the original data. The disk image is read-only.
Read/write: Allows you to add files to the disk image after it’s created.
DVD/CD master: Can be used with third-party apps. It includes a copy of all sectors of the disk image, whether they’re used or not. When you use a master disk image to create other DVDs or CDs, all data is copied exactly.
To encrypt the disk image, click the Encryption pop-up menu, then choose an encryption option.
Click Save, then click Done.
Disk Utility creates the disk image file where you saved it in the Finder and mounts its disk icon on your desktop and in the Finder sidebar.
Important: Don’t create a disk image of a disk that you believe to be failing or that contains corrupted information. The disk image may not serve as a reliable backup.
For technical information about creating a restore disk image, see the Apple Software Restore (ASR) manual (man) page.
Create a disk image from a folder or connected device
You can create a disk image that contains the contents of a folder or connected device, such as a USB device. This method doesn’t copy a device’s free space to the disk image. For example, if a USB device or volume is 80 GB with 10 GB of data, the disk image will be 10 GB in size and include only data, not free space. You can then restore that disk image to another volume.
In the Disk Utility app on your Mac, choose File > New Image, then choose Image from Folder.
Select the folder or connected device in the dialog that appears, then click Open.
Enter a filename for the disk image, add tags if necessary, then choose where to save it.
This is the name that appears in the Finder, where you save the disk image file before opening it.
To encrypt the disk image, click the Encryption pop-up menu, then choose an encryption option.
Click the Image Format pop-up menu, then choose an option:
Read-only: The disk image can’t be written to, and is quicker to create and open.
Compressed: Compresses data, so the disk image is smaller than the original data. The disk image is read-only.
Read/write: Allows you to add files to the disk image after it’s created.
DVD/CD master: Can be used with third-party apps. It includes a copy of all sectors of the disk image, whether they’re used or not. When you use a master disk image to create other DVDs or CDs, all data is copied exactly.
Hybrid image (HFS+/ISO/UDF): This disk image is a combination of disk image formats and can be used with different file system standards, such as HFS, ISO, and UDF.
Click Save, then click Done.
Disk Utility creates the disk image file where you saved it in the Finder and mounts its disk icon on your desktop and in the Finder sidebar.
Mac Disk Utility For Windows
For technical information about creating a restore disk image, see the Apple Software Restore (ASR) manual (man) page.
Create a secure disk image
If you have confidential documents that you don’t want others to see without your permission, you can put them in an encrypted disk image.
Note: If you want to protect the contents of the system disk, turn on FileVault using the FileVault pane of Security & Privacy Preferences.
In the Disk Utility app on your Mac, choose File > New Image > Blank Image.
Enter a filename for the disk image, add tags if necessary, then choose where to save it.
This is the name that appears in the Finder, where you save the disk image file before opening it.
In the Name field, enter the name for the disk image.
This is the name that appears on your desktop and in the Finder sidebar, after you open the disk image.
In the Size field, enter a size for the disk image.
Click the Format pop-up menu, then choose a format:
If you’re using the encrypted disk image with a Mac computer using macOS 10.13 or later, choose APFS or APFS (Case-sensitive).
If you’re using the encrypted disk image with a Mac computer using macOS 10.12 or earlier, choose Mac OS Extended (Journaled) or Mac OS Extended (Case-sensitive, Journaled).
Click the Encryption pop-up menu, then choose an encryption option.
Enter and re-enter a password to unlock the disk image, then click Choose.
WARNING: If you forget this password, you won’t be able to open the disk image and view any of the files.
Use the default settings for the rest of the options:
Click the Partitions pop-up menu, then choose Single partition - GUID Partition Map.
Click the Image Format pop-up menu, then choose “read/write” disk image.
Click Save, then click Done.
Disk Utility creates the disk image file where you saved it in the Finder and mounts its disk icon on your desktop and in the Finder sidebar.
In the Finder , copy the documents you want to protect to the disk image.
If you want to erase the original documents so they can’t be recovered, drag them to the Trash, then choose Finder > Empty Trash.
When you’re finished using the documents on the secure disk image, be sure to eject the disk image. As long as it’s available on your desktop, anyone with access to your computer can use the documents on it.
Download Mac Disk Utility
To access the data in a disk image, double-click it. It appears on your desktop, and you can add, remove, and edit files on it just as you would with a disk.
When Apple updated Yosemite to Mac OS X El Capitan, it made huge changes to the Disk Utility. The streamlined interface is easy to use, but it’s missing some key functions. Some of them are there though if you know where to look.
Repairing Permissions in El Capitan
The most obvious feature that Apple seemed to take away was rRepair permissions. That feature solved a few Mac problems, but, for the most part, was unnecessary. The operating system checks permissions during software updates. At other times, those permissions aren’t allowed to be changed. Repairing permissions can still be an effective troubleshooting step. Some tech support providers won’t help you unless you repair those permissions. There are a few different ways to do it.
Cool El Capitan Features: If you recently upgraded, check out how to use Split View and the upgraded Mission Control.:max_bytes(150000):strip_icc()/ResizeDiskUtilityElCap-56b3defa3df78c0b135383d8.jpg "Best")
If you like using terminal, this command will repair permissions.
sudo /usr/libexec/repair_packages --repair --standard-pkgs --volume /
If you don’t like messing around in Terminal, MarcPac wrote RiparaCapo. That free app does all the repair permissions behind the scenes. I think it’s a little safer to run that program as a terminal is a powerful tool on a Mac.
Secure Erasing a Volume
In previous Disk Utilities, you could specify how you wanted a volume erased under options. Originally, Apple gave you a 35-pass method as the most secure erase method. In Lion and later versions, Apple removed that option and left you with a 7-pass erase as the most secure. That’s enough for most users.
Securely deleting files: You don’t have to erase the entire drive to securely erase a file. You can do this through terminal with thediskutil command. Apple removed Secure Empty Trash and replaced it with 
Delete Immediately.To access that option in El Capitan, you’ll need to select a Volume rather than a physical disk. If the disk is unformatted, you won’t be able to secure erase it. That’s an annoying change.
Again, the command line comes to the rescue. You can specify a 34-pass erase using the secureErase command. Without the GUI of OSX protecting you, it’s easy to select the wrong disk to erase. I’d avoid using this command unless the Disk Utility isn’t working for you.
Creating a RAID
I’m not sure why Apple removed this from the main Disk Utility. Most likely the reason is simplicity. Creating a RAID is specialized functionality so they left it to Terminal and the diskutil command. Also, improper use of the RAID function could cause problems with the Fusion drive scheme.
Another option is to reboot your Mac into Recovery Mode. The Disk Utility in recovery mode does support creating a RAID.
Disk Repair and First Aid
The options for repairing a disk changed. Instead of Verify Disk and Repair Disk, the options merged. Now you select the volume and click First Aid. That saves a few steps from previous versions.
Serious errors still need advanced utilities like Disk Warrior to fix the system.
Burning a Disk
While most new Macs don’t have an optical drive, some of us still need to burn CDs and DVDs. Disk Utility was a great way to copy a disk or convert it to an ISO. Apple removed those features in El Capitan.
Need to copy a hard drive? Check out our guide to creating a bootable backup.The good news is most of these functions moved to the Finder. If you select an ISO or other master image file and right-click, you’ll see a Burn Disk Image to Disc option. That saves you a few steps compared to using Disk Utility. If you want to burn a folder or file to a CD or DVD, right-click the item and select Burn to Disc.
If you want to create an image from an optical drive the process is the same as it was in previous versions. From the File Menu in Disk Utility select New Image and then pick Image From and the name of the item you want to copy. Under Format, if you want to be able to burn a copy, pick DVD/CD Master. That creates a .CDR file that you can burn directly from the Finder.
Encrypted Volumes: To keep your files secure, consider creating an encrypted volume or folder.New Feature: Disk Overview
This is a similar overview you get when you go to About This Mac and select Storage. The key difference between the two views About The Mac shows how much space is taken by backups. Otherwise, the views are the same. Disk Utility adds some information that’s useful in Terminal like what device it is and the drive format. I think it’s a waste having it in both places.
Most Everything Else is the Same
Other than these changes, most of the features remain the same. Creating a volume with different formats is the same. Erasing a PC formatted drive is still the same, although the button placement moved.
ALSO SEE: Alfred vs Spotlight: Which Works Best at Finding Stuff on Your Mac?
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Did You Know
The term Wi-Fi doesn’t have a full form.