MacDisk is an utility to read/write/format Macintosh media on a PC without any add-on. MacDisk manages floppies, CD-ROMs, Zips, Jaz, all removable media and even plain hard disks. Disk Utility can find and repair errors related to the formatting and directory structure of a Mac disk. Errors can lead to unexpected behavior when using your Mac, and significant errors might even prevent your Mac from starting up completely.
Disk Utility User Guide
In Disk Utility on Mac, you can erase and reformat storage devices to use with your Mac. Erasing a storage device deletes everything on it.
- If you have any files you want to save, copy them to another storage device.
- Open the Disk Utility app on your Mac using one of the following methods, depending on the type of disk or volume you want to erase:
- If you want to erase your startup disk or startup volume: Start up from macOS Recovery, then choose Disk Utility from the macOS Utilities window.
- If you want to erase any other type of disk or volume: Double-click Disk Utility in the /Applications/Utilities folder.
- Choose View > Show All Devices.
- In the sidebar, select the storage device you want to erase, then click the Erase button .
- Click the Scheme pop-up menu, then choose GUID Partition Map.
- Click the Format pop-up menu, then choose a choose a file system format.
- Enter a name.
- (Optional) If available, click Security Options, use the slider to choose how many times to write over the erased data, then click OK.Secure erase options are available only for some types of storage devices. If the Security Options button is not available, Disk Utility cannot perform a secure erase on the storage device.Writing over the data three times meets the U.S. Department of Energy standard for securely erasing magnetic media. Writing over the data seven times meets the U.S. Department of Defense 5220-22-M standard.
- Click Erase, then click Done.
Note: With a solid-state drive (SSD), secure erase options are not available in Disk Utility. For more security, consider turning on FileVault encryption when you start using your SSD drive.
See alsoApple Support article: How to erase a disk for MacPartition a physical disk in Disk Utility on MacFile system formats available in Disk Utility on MacFormat a disk for Windows computers in Disk Utility on MacEncrypt and protect a storage device with a password in Disk Utility on Mac
Disk Utility can find and repair errors related to the formatting and directory structure of a Mac disk. Errors can lead to unexpected behavior when using your Mac, and significant errors might even prevent your Mac from starting up completely.
Before proceeding, make sure that you have a current backup of your Mac, in case you need to recover damaged files or Disk Utility finds errors that it can't repair.
Open Disk Utility
Start up from macOS Recovery, then select Disk Utility from the Utilities window. Click Continue.
If you're not repairing the disk your Mac started up from, you don't need to start up from macOS Recovery: just open Disk Utility from the Utilities folder of your Applications folder.
If you're not repairing the disk your Mac started up from, you don't need to start up from macOS Recovery: just open Disk Utility from the Utilities folder of your Applications folder.
![Disk utility on mac Disk utility on mac](/uploads/1/2/6/3/126343533/648025492.jpg)
Locate your disk in Disk Utility
Choose View > Show All Devices (if available) from the menu bar or toolbar in Disk Utility.
The sidebar in Disk Utility should now show each available disk or other storage device, beginning with your startup disk. And beneath each disk you should see any containers and volumes on that disk. Don't see your disk?
In this example, the startup disk (APPLE HDD) has one container and two volumes (Macintosh HD, Macintosh HD - Data). Your disk might not have a container, and it might have a different number of volumes.
Disk Utility Mac Download Free Download
Repair volumes, then containers, then disks
For each disk that you're repairing, start by selecting the last volume on that disk, then click the First Aid button or tab.
Disk Repair Utility For Mac
In this example, the last volume on the disk is Macintosh HD - Data.
Click Run to begin checking the selected volume for errors.
- If there is no Run button, click the Repair Disk button instead.
- If the button is dimmed and you can't click it, skip this step for the item you selected, and continue to the next item.
- If you're asked for a password to unlock the disk, enter your administrator password.
After Disk Utility is done checking the volume, select the next item above it in the sidebar, then run First Aid again. Keep moving up the list, running First Aid for each volume on the disk, then each container on the disk, then finally the disk itself.
In this example, the repair order is Macintosh HD - Data, then Macintosh HD, then Container disk2, then APPLE HDD.
If Disk Utility found errors that it can't repair
If Disk Utility found errors that it could not repair, use Disk Utility to erase (format) your disk.
If your disk doesn't appear in Disk Utility
If Disk Utility can't see your disk, it also can't see any containers or volumes on that disk. In that case, follow these steps:
Free Mac Disk Utility
- Shut down your Mac, then unplug all nonessential devices from your Mac.
- If you're repairing an external drive, make sure that it's connected directly to your Mac using a cable that you know is good. Then turn the drive off and back on.
- If your disk still doesn't appear in Disk Utility, your disk or Mac might need service. If you need help, please contact Apple Support.