By now I'm sure you've heard that external FireWire 800 drives using the Oxford 922 chip-set may lose data when you connect them to a Mac running Mac OS X 10.3 Panther. If you haven't, Apple offers an information page at http://www.apple.com/macosx/firewire800specialmessage.html:

A special message for FireWire 800 disk drive users

Apple has identified an issue with external FireWire hard drives using the Oxford 922 bridge chip-set with firmware version 1.02 that can result in the loss of data stored on the disk drive. Apple is working with Oxford Semiconductor and affected drive manufacturers to resolve this issue which resides in the Oxford 922 chip-set.

In the interim, Apple recommends that you do not use these drives. To stop using the drive, you should unmount or eject the disk drive before doing anything else. Please check this web page for further updates.

Update 11/4/2003:
Apple and Oxford Semiconductor have confirmed that firmware version 1.05 resolves the data loss issue experienced by some FW800 users. FireWire disk drive manufacturers have begun posting firmware updates:

Century Global
Ezquest
Firewire Depot
FirewireDirect
Glyph
Lacie
Macpower
Other World Computing
Wiebetech

Only use the updater provided by the maker of your drive and follow the installation instructions carefully. If your drive manufacturer is not listed, contact them for more information.

This message, third party links and related information are provided by Apple for information purposes only, without representation and warranty of any kind. Apple expressly disclaims any liability relating to the use of this message, third party links and related information. Any questions regarding third party support should be directed to the appropriate third party.

OK. No biggie here at Casa Del LeVitus -- I'm too cheap to spring for FireWire 800. (And, of course, even if I weren't too cheap, I'd get no benefit from 'em -- none of the Macs I own support FW800).

So I felt pretty darn safe until this morning, when I noticed that a number of Mac Web sites -- including MacInTouch and MacFixIt -- had bits and pieces that appear to imply that plain old FireWire 400 hard disks may lose data when used with Panther.

Uh oh… I don't feel very safe anymore.

You see, I've got FireWire 400 drives galore -- half a dozen on my desk alone. But what scares me most is that I use FireWire 400 drives as my primary backup medium. I have a set of Retrospect scripts that back up my Home and Work directories to three external FireWire 400 disks, in rotation, every two hours.

All of a sudden I'm afraid. No, make that very afraid. Wait…make it very, very afraid.

Maybe I'm paranoid, but I'm doing a whole bunch of stuff I wouldn't ordinarily do to insure that my data remains safe and sound, at least until I feel confident that my FireWire 400 disks aren't at risk with Panther:

I am backing up my boot disk to DVD-RW discs as I type this and creating scripts that will back up my most-important files to DVD-RW every two hours.

Once the DVD-RW backup is completed and verified, I'll update the firmware on all of my FireWire drives using the latest firmware patches available from the manufacturers.

I am backing up critical files to my iDisk daily.

I will un-mount and physically disconnect all my FireWire drives before shutting down or restarting (which, fortunately, are both things I do infrequently…)

Why? There has been some indication doing so avoids the issue that affects FireWire 800 drives. So even though there's no evidence it helps FireWire 400 disks, I'm doing it anyway. Better safe than sorry.

I am checking sites like MacInTouch and MacFixIt daily for additional information regarding FireWire 400 drives.

I am praying daily to Zulch, the God of data integrity.

Is all this overkill? I think not. I'm busting my butt to finish Dr. Mac: The OS X Files, Panther Edition and I don't have the time or the temperament to deal with lost data. I suppose I could regress to OS X 10.2.8, Jaguar, which hasn't had problems like these reported, but I don't like Jaguar anymore and I'm writing almost exclusively about Panther these days. So, in keeping with my "eat your own dog food" philosophy, I need to run Panther on my Mac even if it hurts a little. (The truth is, I have to do it even if it hurts a lot. And all this extra work definitely hurts a lot.)

The big question is: Should you be doing something like this? The answer is: I have no idea. Only you can decide how important your data is to you. My advice: If you have external FireWire drives, are running Mac OS X Panther (which, by the way, totally rocks otherwise), and care about your data, you probably ought to do something, or else switch back to Jaguar until more is known about these lost data issue(s), what causes them, and how to avoid them...

As for me, I'm off to Fry's... I need to buy another stack of DVD-RW discs.