The disk utility on a Mac is like the basis of any action that we want to carry out with any hard drive that we have connected to the Mac. Whether internal or external, it is the fundamental and key piece for us to be able to carry out certain actions. That is why it is important to be able to have as exhaustive knowledge as possible about it. Not only will we be able to manage connectivity with the disks, we will be able to do many more functions that we will try to show you now in this article.
The Disk Utility that Apple has integrated into macOS and that can be accessed on any Mac is essential to be able to dealing with the computer on a day-to-day basis and be able to connect external devices. But above all we can perform certain actions also with the internal hard drive. Please note that we may format and manage volumes on physical storage disks. Create a disk image, which is nothing more than a single file that allows you to transfer files to other computers or compress and save backup copies of your work. But we can also combine several hard drives in a RAID group and work as a single drive. Find errors and many more features. For example, we are going to leave you some very useful ones here right now.
Resizing disk images
Sometimes we need to be able to change the size of a hard drive because we want to divide it in two, for example. Being a very high capacity hard drive, we can take advantage of it to make a division and thus have two instead of one. To change the size of a disk image, the first thing we have to do is unmount it. In other words, it should not be connected to the Mac. To do this we can either drag it to the trash can or use the eject symbol external drive that we have in the sidebar of Disk Utility.
Once unmounted, choose Images->Resize from the Disk Utility main menu. This opens the standard file opening panel, from which you can select a disk image file of the disk.
Convert a disk image to another format
On other occasions, we may want to convert a hard drive that has one extension to another because it suits us better or because the place where we are going to connect it later requires it due to special circumstances in its encryption. But it is also useful if we want to change the properties of the hard drive, for example changing the format to read-write, or vice versa using the image conversion function.
To convert an image, select Images > Convert in the main menu. This opens the standard file opening panel where you can select any existing disk image file previously saved to the disk. In this case, the window of opportunity opens for us to choose a format that we could not otherwise. This is the hybrid image (HFS+/ISO/UDF). This format is a multi-volume format that can combine several other formats into a single image.
One of the best extensions to use is the system call APFS by which we can see periodic snapshots that the Apple file system performs at certain intervals. Shadow copies are a redundancy feature and help ensure recovery if a volume becomes damaged. So good is this extension that it sometimes has the ability to recover damaged volumes by comparing data on a volume with previously saved snapshots, to try to determine what the damaged data is.
If we want to convert a volume to this versatile system, the APFS, from, for example, the HFS+ first select the volume in the sidebar of Disk Utility, then select Edit->Convert to APFS from the main menu, either hold down Control and click or right-click the volume in the sidebar and select Convert to APFS on the popup menu. Please note that this operation is risky and if it fails halfway, we may lose all data. So be careful and be very clear about your decision.
Once this is done, we’ll get a confirmation warning asking if we’re sure we want to do this. You have to know that APFS volumes they cannot be used with earlier versions of macOS and that you cannot undo the conversion.
Password protection of a device
Another interesting option is to protect a hard drive with a password to safeguard our data. Of course, make sure to make a backup copy first because the first step we must do is erase the storage disk. We will format it as “APFS Encrypted«. This encrypts the data on the device and protects it with a password. Every time we want to use the Mac, we must enter a password.
If we have configured the internal hard drive in this way, the one that has the Mac boot, every time we turn on we must confirm that password. From Disk Utility, we select the option in the sidebar, and then click the Erase icon in the main window toolbar. We will be prompted for a new volume name, click the Format: dropdown menu and select APFS (Encryption). The new password will be requested again.
Disk Utility will try to erase the device and we will be notified if it has been successful or not. Once we have a device that is password protected, we can change it by selecting it in the sidebar and then selecting File->Change Password from the main menu. By the way, we can also rename an existing volume by selecting it in the sidebar of Disk Utility, then choosing File->Rename in the main menu.
There are many more functions of Disk Utility but I thought that these could be very good because they are less known. I hope it works for you and helps you and for future reference