Instructions
Format your external hard drive in the "FAT32" file system. To do this, connect your hard drive to your computer and open the "My Computer" desktop icon. Right-click on the drive's icon in "My Computer." Click the "Format" button. Click "FAT32" from the "File Type" drop-down menu. Then, click "Start." This will format your external hard drive in the "FAT32" file system.
Right-click on the drive's icon in "My Computer" and click "Eject" after the formatting process is complete. This will "unmount" the drive from your operating system, allowing you to safely remove it without the worry of losing any data.
Unplug your hard drive from your computer.
Plug the USB hard drive cable into a USB port on the rear of your PS3.
Turn on your PS3. During the booting process, your system will immediately recognize the external hard drive, and its storage space will be available for use by the console.