Useful Tips

External hard drive for MacBook: how to work with the device


Learn how to use and troubleshoot a FireWire external drive mode.

FireWire external drive mode allows you to use a Macintosh computer with a FireWire port (target computer) as an external hard drive connected to another (main) computer. After the target computer running in the FireWire hard drive mode becomes available for the main computer, it will be possible to copy files both from it and to it.

Main Computer Requirements

The host computer must have the following characteristics:

  • FireWire port (built-in or on a PC Card adapter),
  • FireWire version 2.3.3 or later,
  • Mac OS 8.6 or later.

Target computers

The following models can be used as target computers.

  • iMac (with slot loading) with firmware version 2.4 or later
  • iMac (summer 2000) and all models released after July 2000
  • eMac (all models)
  • Mac mini (all models)
  • Power Mac G4 (with AGP graphics card) with ATA hard drive
  • Power Mac G4 Cube
  • Power Mac G4 (Gigabit Ethernet) and all models released after July 2000
  • Power Mac G5 (all models)
  • Mac Pro (all models)
  • iBook (FireWire) and all models released after September 2000
  • PowerBook G3 (FireWire)
  • PowerBook G4 (all models)
  • MacBook Pro (all models)
  • MacBook models released before October 2008

Note. FireWire external drive mode works only for internal PATA and SATA hard drives. External drive mode is enabled only for the main PATA hard drive on the Ultra ATA bus. Connecting to hard drives such as slave ATA, ATAPI, and SCSI is not supported.

Before you start working with FireWire external drive mode, check the following.

  • Make sure the latest software and firmware are installed.
  • Before you start working with FireWire external drive mode, disconnect all other FireWire devices from both computers. Do not connect any FireWire devices while the computers are connected to each other or the external drive mode is used.
  • If Open Firmware Password is enabled, the computer will not work in external disk mode. For more information on Open Firmware Password, see the section “Actions to Take if Your Mac Does Not Go into FireWire External Drive Mode” in this article.
  • To transfer user folders protected by FileVault (Mac OS X 10.3 and later only), you must log in using a FileVault user account and temporarily disable FileVault. After completing the transfer of the contents of the user folder to the target computer, you can re-enable FileVault protection if necessary.

Switching to FireWire External Drive Mode

  1. Make sure the target computer is turned off.
  2. If you use an Apple laptop, such as a PowerBook or MacBook, as the target computer, connect its AC adapter to the AC adapter.
  3. Use a FireWire cable to connect the target computer to the host computer. In this case, the main computer can be turned on.
  4. Start the target computer and immediately press and hold the T key until the FireWire icon appears. The hard drive of the target computer will become available to the main computer, and the corresponding icon will probably appear on the desktop. (If the target computer is running Mac OS X 10.4 Tiger, you can also open the program System settingsclick icon Boot volumeand then press the button External drive mode. After rebooting, the computer will start in external drive mode.)
  5. When the copying of files is completed, find the hard drive icon of the target computer on the desktop of the main computer and drag it to the trash or select Eject (or Disable) on the menu File.
  6. Turn off the target computer using the power button.
  7. Unplug the FireWire cable.

Guidelines for Using Target Disk Mode on Intel-Based Macs

When you try to connect a Mac computer with an Intel processor in external drive mode to a Macintosh computer running Mac OS X 10.3.9 or earlier, a warning message appears. For more information, see Mac computers with an Intel processor: warning message "You inserted a disk that doesn’t have readable volumes on Mac OS X."

If a Mac with an Intel processor in external drive mode stops responding, see Mac with an Intel processor may stop responding while in external drive mode.

Actions to Take If Your Mac Does Not Go Into FireWire External Drive Mode

If after holding the T key during startup, your Mac does not go into FireWire external drive mode and instead loads Mac OS, follow these steps:

  1. Make sure the FireWire cable is OK and check the connection.
  2. Make sure the rest of the FireWire devices are turned off.
  3. Make sure you boot the computer by pressing and holding the T key.
  4. Check keyboard connection. Make sure the keyboard is connected directly to the computer, and not through a display or hub. Whenever possible, use the Apple Wired or Wireless Keyboard.
  5. Make sure that Open Firmware Password is not enabled on this computer. Depending on the version of the operating system, you may need to download Open Firmware Password software. For more information on Open Firmware passwords, see Configure low-level password security on Mac OS X.

Why is this needed?

At first glance, it might seem that this is quite inconvenient. It may seem so because the external drive takes up a lot of space. Why use it if there are compact flash drives, or in extreme cases regular discs?

It's all about volume. A flash drive can be quite large, even 64 gigabytes. However, external hard drives can have 500 gigabytes of memory in themselves, and these are still small indicators. The most expensive external drives can have several terabytes of memory inside, which is much more than a flash drive can accommodate.

But these are far from all the benefits.

  1. The fact is that a flash drive can only work with computers. But the external hard drive can be put almost anywhere. It can be used as a storage of data from a video camera, or in order to record data in other places. They can be easily inserted, after which it is also easy to read.
  2. It is also worth considering the fact that external storage devices are much more reliable than flash drives. The fact is that breaking a USB flash drive is much easier than an external drive, but this is not the most important thing. The main thing is that the data stored on the flash drive can easily disappear as a result of failures. But with external hard drives, such situations happen much less often.

As you probably already understood, it is much more reliable and convenient to buy special external drives. They should buy readers, in which they will be constantly. In such devices, disks can be put in a backpack, and carry terabytes of memory with you, while not feeling any load. It is very convenient, and not very expensive.