Troubleshooting FireWire drives

Time Machine and other backup programs have boosted demand for external hard drives. To meet this demand, drive manufacturers began marketing their products in external enclosures, but have not always incporated the most compatible chipsets and controllers, which can result in various problems.

Apple Discussions poster Bryce Inman writes:

"I've got an external Western Digital firewire drive that's been somewhat flaky recently, and today my Mac won't mount it. When I open Disk Utilities, I can see the drive (along with the other drives daisy chained together). When I click on "mount," I get a message saying the drive can't be mounted and that I should try running disk repair."

These problems can stem from a variety of issues, including Mac incompatibility, drive failure, low power, or incompatibility with either another third-party software or hardware solution (other drives, drivers, utility software, etc). The following troubleshooting steps may help determine if the drive itself is malfunctioning.

Troubleshooting

• Try connecting just the drive Many times drives draw power from the computer instead of running off their own power supply. This is especially true for portable drives. If users have multiple such drives on the same FireWire bus, low power may prevent the drive from working properly, even if there are no warnings. By connecting the drive either in another position in a daisy chain, or removing all other devices except the drive, users can test power problems to the drive. Additionally, many drives that use bus power optionally come with external power sources, and it is recommended to plug these in as well.
• Try using another connector (ie: USB instead of FireWire, if supported) Many drives may have FireWire 400 as well as FireWire 800 ports, and it is recommended to try all the ports. In many cases, users will be able to mount the problematic drive perfectly fine via USB.
• Try on another Mac Users may have third-party software installed which is interfering with the drive's functions. Users can try mounting the drive on another computer, or booting off the Leopard DVD and running Disk Utility to test the drive and try to mount it.
• Try on a Windows PC (or BootCamp) Since the controllers should technically be universal, users can try connecting the device to a Windows PC to see if it is properly recognized. If the drive is formatted as FAT32, it should mount properly; however, if it's in HFS format it will not mount but still should be recognized as an external hard drive device

If any of these steps work, more than likely the drive itself is working fine. Users should then try power cycling the drive (turning it off for a few minutes, unplugged from all devices and power, and then back on). Additionally, restarting the computer and resetting the PRAM may also help clear problematic settings that may interfere with communication with the device. Booting into Safe Mode (holding shift at startup) might also help users determine if a software incompatibility is the problem.

Tip for new drive purchases -- Buy "Mac" editions While these products should technically be universal, manufacturers resort to some I/O controllers that only work on Windows PCs, which prevents some models from working properly on the Mac. For instance, Seagate has a series of "FreeAgent" drives which will not work properly via FireWire on some Mac models; however, they do have a "Mac" version that is properly tested and works as advertised. Many buyers may think that "USB" and "FireWire" indicate users at most only need to format for mac compatibility, but this is not always the case. "Mac" editions of drives are shipped with controllers that are known to be compatible with the Mac OS and supported hardware.

Alternatives

While buying an external drive package may be convenient, another option is to purchase the drive and enclosure separately. Mac-specific hardware vendors such as Other World Computing have a collection of enclosure types for various drives. When purchasing an external enclosure solution, it is recommended to look for an "Oxford" I/O chipset, which has been known to perform well and be very compatible with the Mac OS. These chipsets are also compatible with Windows, so users will not have to worry about platform-specific errors.

Along with the enclosures, users will just need to buy any internal 2.5" or 3.5" sATA or IDE hard drive and install it in the enclosure. Drives themselves are universal, and compatibility problems come from the controller used, and not the drive itself. Therefore, as long as the enclosure is sold as being "Mac Compatible", users should be able to mount any drive that will fit in the enc

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