Format a Hard Drive Using Mac OS X Disk Utility

Posted May 9, 2008 at 12:08am by iClarified | Please help us and submit a translation by clicking here | 162048 views

These are instructions on how to format a hard drive using Mac OS X Disk Utility.

Step One
If your hard drive is an external drive, connect it to the computer. Launch Disk Utility from the Applications:Utilities folder.

Step Two
From the list on the left select the drive you would like to format

Step Three
Click to select the Erase tab.

Step Four
From the Volume Format dropdown select the format you would like the drive to be in.

Step Five
Enter the title for your volume in the Name field.

Step Six
Press the Security Options... button to specify how to erase the drive. You can choose: Don't Erase Data, Zero Out Data, 7-Pass Erase, or 35-Pass Erase. Click the OK button to continue.

Step Seven
You are now ready to begin the format. Click the Erase... button to start.

Step Eight
From the popup that appears click the Erase button to confirm you would like to format.

Step Nine
You will notice a status bar appear with the progress of your format.

Step Ten
Once the format has completed you will notice the disk remount in Disk Utility!

Add Comment
WarmHen - July 11, 2014 at 4:24pm
A huge thank you for demystifying this process. Worked like a charm.
Rob Lowthian - April 26, 2014 at 10:42am
This was the best advice I had when trying to reformat a Seagate 2TB Expansion external hard drive to my Mac (OSX 10.6.8). The reformat would not work until I discovered Step 6 from this description. The reformat worked immediately. Thank you so much to whoever is responsible for this!
xavl - January 17, 2014 at 11:55am
Following these steps I get stuck after clicking Erase with the error "Disk Erase failed / Disk Erase failed with the error / Couldn't unmount disk." Verify Disk sees no problem with the whole disk. There is one partition for which Repair Disk gives the message: "Error: Disk Utility can’t repair this disk. Back up as many of your files as possible, reformat the disk, and restore your backed-up files." Is there a way to reformat the disk that does not require a mount point?
Emma - November 10, 2013 at 5:39am
I'm trying to transfer files from my MacBook Pro onto a hard drive, I've formatted the hard drive the same way as in the introductions above but when I tried plugging it into a Windows computer it didn't show up. Is one of the other formats both Mac and Windows compatible?
leho - September 26, 2013 at 10:55pm
oh thank you so much for the useful info!
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