Formatting an external drive for use with an Apple Mac

Before you can use a new (or old) drive with a Mac you will need to format it. There are several options which we will look at to help you choose the correct format for you and show you how to ready the disk for use

Step 1: Launch Disk Utility

Open Applications > Utilities, which is found through Finder, then open the Disk Utility application.

You should see a list of available drives. Choose the drive you’d like to format, and then select/click the Erase option.

Step 2: Choose your desired format

Disk Utility automatically defaults to the OS X Extended (Journaled) file system format, but you can choose a different option by selecting Formatting options.

OS X Extended (Journaled) – this is the default (and recommended) format for creating secure password-protected drives. You can also Encrypt your internal laptop drive, as well as any external drives, which is a great idea if you carry around additional portable drives and want to keep your data secure in the case that you lose that drive or laptop. Encryption can also be applied USB any key drives that you use. For more information on this please click HERE

Mac OS Extended (Case-Sensitive, Journaled) – if you wish to identify and differentiate files by lower and upper-case files on a drive; this type of format will allow the file system to treat case sensitive files as separate individual files. For example a file named MyFile.txt and myfile.txt would be treated and handled as two separate individual files.

MS-DOS (FAT) – if you wish to share this drive with a Windows PC, Playstation 3, Xbox 360 or One or a Linux based Operating System then you can choose this option (be aware of file size limits using FAT See Here). You may also choose this opion if you wisjh to create a Bootcamp partition, in order to install and run Windows on your Mac.

ExFAT – the same as for MS DOS (FAT) above, only this option has been optimised for flash drives – both internal and external.

Choose Your Mac OS File System


Step 3: Name your drive

Once you’ve chosen the drive format you want to use, you’ll need to name the drive.  Ideally you want to name it something relevant like ‘Bob’s Main HD’ for the internal laptop drive or ‘My Videos & Pictures’ if you’re using the drive externally to store videos and images, etc.

Step 4: Choose a security option

Select ‘Security Options’ to select the security level on the drive, using a slider ranging from Fastest to Most Secure.

Fastest will erase the drive by removing the header information, but will leave the underlying files intact, although they will be hidden. This means you or someone else could resurrect the files easily using data-recovery software, which isn’t necessarily a good idea.

For a fresh install of OS X, move the slider to the second option “This option writes a single pass of zeros over the entire disk.” This will overwrite the entire drive once.

For the highest level of security, move to the slider one more step to the right, which will overwrite the drive three times. Moving it all the way to the Most Secure option will overwrite the drive seven times – which will take a lot longer but offers the most secure way of removing any old data.

Set Security for your new Mac OS Drive

Step 5: Format the drive or USB

The final step is to select the Erase button, Formatting a drive can be a lengthy process, depending on – 1. the size of the drive and 2. the Security Options selected. A progress bar will display the time elapsed and how much time (approximately) remains until formatting is complete.

Once the above process is complete your drive will be ready to use.

See our range of External Hard Drives – CLICK HERE

For more information on Drive File System Compatibility across different Operating Systems click HERE

To See how to format a new drive for use with Windows 10 click HERE


Now you know which of your computers, laptops, tablets, games consoles, tablets and mobile phones can share information with each other why not invest in an external storage device (Portable Hard Drive)  – see the full available range here: – CLICK HERE

Buy An External Hard Drive From


To find out how to format a disk drive for use with Windows 7, 8 or 10, click HERE

Format External Disk Drives for Windows 10 7 8

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