There's been a lot of coverage this week of the possibility of losing your data on your Mac, and if there's anything that should make you backup your data, this post should put the fear of [pick your diety] in you.

Possible Bad Series of Drives in MacBooks?

First off, there are reports of a recurring problem with Seagate drives used in the Apple MacBook, as covered by numerous sources. This drive recovery company shows the evidence:

http://www.retrodata.co.uk/notice_apple_seagate_drives.php

Basically anyone with a MacBook needs to check their drive version to make sure that they're not running one of these drives. To do so, go to the Apple Menu and hit "About This Mac..."

Then hit the "More Info..." button at the bottom of that window, which will open System Profiler.

Once there, hit "Serial-ATA" on the left side and look for the Revision under the disk.

In this case, I'm using a Fujitsu drive with revision 00810013. But if you see Seagate and revision 7.01, you should consider backing up your files immediately. Then again, we always recommend that you backup your files - because suspect drive or not, you will eventually experience a hard drive crash.

While there's no official recall on this drive (and we're in no position to judge whether or not it's needed), Paulo Rodrigues of our In-House Services has observed that if this drive fails, it's almost impossible to recover the data from the drive, no matter how much money you spend on it.

Is It Possible to Lose Data When Moving Files from Disk to Disk?

Add to that the latest bit of scary news: what some are calling a "bug" in Leopard, but others are saying has been a persistent problem since 10.3. Whatever you call it, Ian Blanton, our Dir. of Field Services has verified it - you can lose data when moving data from one volume to another in a specific way.

The scenario is as follows. Let's say that you're going to move your files to a USB Flash drive. Thinking that you don't want the files on your hard drive after they are copied over, you do the "command-drag" shortcut, holding down the command key while dragging the files to the Flash drive.

Normally, if you're doing that on the same disk, this will make a copy instead of moving the files. However, when moving files from disk to disk, it will copy the files and then delete them on the original disk.

The problem occurs when, in the middle of the copy, something happens - say, you accidentally bump the USB Flash drive and it gets disconnected. Wham. Your copy stops and you would think that your data is still on your hard drive drive, no? Well, our testing has proven that it's not. OS X will delete the original files before it has verified that all of your files got over to the Flash drive.

Now, there's an easy solution to this - never "command-drag" files from disk to disk. I mean, it's a bit of common sense that when copying files from disk to disk, you should just drag the files, then delete the files once the files have come over to the other disk. Still, it's a little scary that this can happen at all.

More details about this "bug" here:

http://www.reghardware.co.uk/2007/11/06/leopard_dataloss_bug_uncovered/

It's all a reminder: always be safe. Never play with matches. And always backup your data.