What is Disk Utility on Mac? Complete beginner's guide

what is disk utility on mac.

What is Disk Utility on Mac

What is Disk Utility on Mac? Here's the Full Explanation

Disk Utility on Mac OS X is an application that allows you to perform very useful and narrow actions. Experienced users often find this handy tool useful, but those who are new to Mac are often warned to stay away for good reason. Today, I'll briefly explain what Disk Utility is, when to use it, and how to avoid deleting important information.

Where can I find Disk Utility on Mac? 

The first confusing thing about Disk Utility is that it can be difficult to find. When I open the application folder, it disappears. Instead, dig a little deeper and open the Utility folder in the Applications folder. The utility folder is in the application folder.

Here you will find many great gifts worth checking out. We have everything from color management to creating data graphs.

To quickly launch the Utility folder from the Finder, just press Command-Shift-U. You can use a similar shortcut Command-Shift-A to open the Applications folder.

Starting Disk Utility

If you find Disk Utility and run it, you'll see a window similar to the following: As you can guess from the title of the application, this is a tool for working with hard drives. Each disc attached to the inside or outside of the machine is displayed in the menu on the left.

disk utility on mac

Disk Utility

When you select a disc from the list, the bottom of this window updates with information about the item. In the screenshot below, I can see that my internal disk is 500 GB, but I'm already using over 300 GB.

disk utility on mac

Disk information

Unfortunately, Disk Utility doesn't explain how to use this storage. This requires a third-party program such as DaisyDisk.

Resolve disk problems with Repair Permissions

A Mac user who has been around for a while says, "If everything else fails, fix the disk permissions." This action is considered a kind of magical cure that addresses all sorts of undetectable problems.

So what are disk permissions, why are they broken, and how are they fixed? Simply put, OS X automatically assigns owners to various files on your computer and also determines the level of interaction that other users may have. Some user accounts have different access rights to certain files. Over time, various installations, removals, updates, etc. can break permissions on certain files.

If many are installed, OSX will write the secret file to / Library / Receipts to notify the system of the permissions. Over time, various installations, removals, updates, etc. can break permissions on certain files. When you restore "disk permissions", you are basically instructing the system to check for secret receipts and recover files whose permissions do not match what they should be.

To do this, click on the disc and then select the First Aid tab near the center of the window. From here, you can check if there are any problems by clicking "Check Disk Permissions".

disk utility on mac

The First Aid tab allows you to check and reset your permissions

If you find a permission issue, you can click "Repair Disk Permissions" to automatically fix the problem on your Mac.

How often do I need to reset my permissions? 

Despite the above anecdote, permission fixes aren't really the end of OS X issues. In fact, I usually take the "when all else fails" approach, as it's probably a very rare case to really solve your problem. The issue of how often permissions are restored is a topic of much debate. When you hear that it's good, you may want to think that you're always doing the right thing-some even swear to do it every day. However, most users will experience this without problems if they perform this action "rare to never."

Most users can do well by performing this action as often as rare to none at all.

Would you like to listen daily or weekly? John Gruber summarizes it well here. 'If you do not experience any symptoms that indicate a permission-related problem, then there is no reason to run recovery permission. Repair permits are not regular maintenance work or precautionary measures. '

The most important point here is that regaining permits is not a precautionary measure. The only reason for this is if you are experiencing permissions-related issues (perhaps after a large installation). I don't know if that's going to go that far, but some even argue that regaining permissions has a 99.9% chance of being useless.

Erase, RAID, and Restore

The other tabs in the central section of Disk Utility are Erase, RAID, and Restore. However, these tabs are the most difficult and usually the place where you're having trouble clicking on something you don't understand.


Note that erasing does exactly what it sounds like!

If you are smart enough, you can probably guess "erase" to delete the data on your hard drive. Note, you can't Command-Z something like that. When you delete a hard disk, it disappears (unless you are familiar with advanced data recovery procedures). My advice: Don't click this tab unless you plan to remove something. In that case, make sure you have selected the correct disk before proceeding.


The RAID tab allows you to create a RAID set using multiple drives

Below is the RAID tab. Here you can use multiple slides to configure mirrored RAID or stripe raids. The first is for backup and the second is for performance.

Mirrored RAID simply replicates the contents of the disk one after another. This is a standard automatic backup, so if your main drive fails, you won't lose any data. This is essential for those who cannot lose their jobs.

Striped RAID is a little different. According to Apple, a striped RAID array stores files on segments (stripes) on all disks in the array. Syrup improves the performance of applications that use large amounts of data. ""


Restore is a misnomer. To understand the purpose of this tab, imagine saying "duplicate". You can use the restore feature to copy the entire contents of your hard drive to another location.

This is a very simple tool with few options. Simply select the source and destination and click Restore to start the backup. If you're looking for something a bit more robust, check out Carbon Copy Cloner

Disk image

Another great use of Disk Utility is to create disk images. The term "disk image" simply refers to a single file that contains the entire contents of the disc. You can create disc images from tabletops, portable discs, and even DVDs. This is typically the format used to clone a hard disk and distribute the software.

To create a disc image, click the desired disc on the left, then click the New Image button. Here you can name the image and configure the destination and its encryption.

Create a disk image

Read the article on this topic for more information on how to use Disk Utility to create a disk image.


The last thing we talked about in Disk Utility is the highlights. The upper button strip.

Disk Utility Basic Options


The first is "verification". This is basically an easy way to verify the disc. Your Mac will appear quickly and report any issues you find. information

The following is "information". This is basically an extension of the basic information we saw at the beginning of this article. This button opens a window similar to the one below.

Information window

Next up is "Info", which is basically an extension of the basic information we saw at the beginning of this article. This button brings up a window like below.

Information window


The Burn button gets a disc image and burns it to a CD or DVD. Useful for backing up various software. It can also be used to create a Lion boot disk. Decrease / emission


If you've spent a lot of time using external chips, you're familiar with mounting and ejecting. When you connect the disc, it will automatically connect to your desktop. We recommend that you press Command-E or drag the disc to the Trash to "eject" the disc. Unmounting and ejecting are functionally the same for external drives. The main difference is that "eject" is to eject a CD or DVD.

So what if you accidentally eject the driver before you finish? Do I need to disconnect? The "Mount" button is useful here. When the disc is ejected, it will be unmounted (not visible on the file system or desktop). Repair by simply pressing "Mount"! Nothing may happen when you insert the disc. If this happens, try opening Disk Utility and setting it up.

Enable Journaling

The last button to explain is "Batch Activation". To help explain what the diary does, I looked at Apple's help page. This is his short and informative explanation:

"Journaling is a technique that helps protect the integrity of Mac OS X extensible file systems on Mac OS X volumes." (Source)

The batch keeps a continuous record of changes to a particular disk, so you can revert to a previous "safe" state in the event of a problem. It is primarily used for servers and should avoid downtime as much as possible. Especially suitable for improving the situation during a power outage.


That sums up the basics of Disk Utility. I hope this guide has given you a good overview of what is possible with this utility, when you should consider using it and what to avoid when you use it. Like most built-in tools, there are often better utilities for some of the functions that Disk Utility performs, but you'll find that it's the perfect general-use utility to quickly deal with all kinds of disk-related activities and problems.

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