Partition and Format a Drive in OS X

Posted on February 7, 2010 at 5:55 am

Partitioning and formatting drives in OS X is much different than it is in Windows, even though the concepts are similar. Apple’s Disk Utility application ships with OS X, and it is simple yet powerful. It gives you a great deal of control over your disks.

Partitioning a Disk

1. Connect your drive to the Mac. If you have an internal hard drive, follow Apple’s instructions for installing it in your machine. If you have an external USB or FireWire hard drive, plug the drive into a port and power it up.

If you are using a Flash drive, simply plug it into the USB port. If the drive is already formatted, OS X will mount it, and it will appear on the Desktop. If OS X cannot read the drive’s format (or if it is not formatted), OS X will prompt you to partition and format it.

2. Launch the Disk Utility application if it has not already launched.

Launch Disk Utility.

3. Choose the disk you wish to partition from the list in the left pane, and then click on the Partition button. The current partition information, if there is any, will appear in the right pane of the window.

Choose the disk.

4. Choose the Volume Scheme from the drop-down menu in the right pane of the screen. If you choose to create multiple partitions, you can resize the partitions by dragging the divider between them on the screen, or clicking on an individual partition and entering the size in the Size field.

Size the partitions and choose the formats.

5. Enter the Name of each partition, and choose the Format from the drop-down menu. If you want to use the partitions on Windows machines, make sure to choose FAT as the format type.

6. If you would like to boot from either of the partitions, click on the Options button. If you would like to boot an Intel Mac, choose the GUID Partition Table. If you would like to boot a PowerPC, choose the Apple Partition Map. If you would like to boot a Windows computer, choose Master Boot Record. Once you are done, click OK.

Make the partition bootable.

7. When you are satisfied with the settings, click Apply. OS X will unmount the disk, repartition it, and mount the partitions on the Desktop.

Formatting a Disk

1. Choose the partition you would like to format from the list of partitions and drives in the left pane.

2. Click the Erase button.

Erase the partition.

3. If security is an issue, click on the Security Options button. You will be given additional erase options, including performing a zero-fill, and performing multiple-pass erases. Choose the option that suits you and click OK.

Secure erase options.

4. When you are satisfied with the settings, click the Erase button near the bottom of the window. OS X will unmount the partition and perform the erase actions you selected. When it is done, it will re-mount the partition.

5. Repeat steps 1-4 for additional partitions and disks you would like to erase.

When you are done, if you would like to shut down, disconnect, or eject the disks, don’t forget to unmount them so your data does not get damaged. To do this, you can drag the disk images on your Desktop to the trash.

» Filed Under Mac OS X

Comments

2 Responses to “Partition and Format a Drive in OS X”

KS said on : March 15th, 2010 at 4:14 pm

Thanks for the article, but I can’t seem to get my internal hard drive recognized by my Mac! I’ve installed it properly, but it’s not showing up in the Disk Utility section. Can’t partition or format it without it showing up.

Sal said on : April 22nd, 2010 at 6:45 am

Thanks for the simple and easy to understand steps for partitioning a hard drive! I’m new to Mac, but need to learn fast.