External hard drive frequently ejects itself when using Aperture I have a brand new external hard drive which frequently ejects itself on a regular basis (every ~20 minutes or so), seemingly only when I have Aperture open (my Aperture library is located on the external hard drive). The disk works perfectly fine for long periods of time when I am not using Aperture.

I have read many places online that this could be related to disk inactivity sleep, disk journaling, Spotlight indexing, faulty Firewire cables, faulty Firewire ports, hard drives which are about to die, etc. However, the disk seems to work perfectly fine when I am not using it for Aperture and none of the many forum threads I have found have pointed me in the right direction.

Does anyone have any ideas on how to identify and fix this issue?

Thanks in advance.
A book was just released by SCSC called "Hard Drive Troubleshooting," which mentions disk ejection in numerous places. The book is free and you can get it by going to:

http://www.scsc-online.com

Go to the downloads section and click on the book to download it.

I would think that if the drive is failing over a specific region, the disk will issue I/O errors and MAY timeout causing the system to think the drive is no longer connected. I believe the book mentions something like a 60 second timeout. To me, that would sound either like bad sectors on the drive OR corrupt data on the drive that the system can't make sense of. For example, if your file xyz.dat is either corrupt or unreadable and it just happens to be read by Aperture (and ONLY Aperature) then the problem would occur only when Aperture in use.

If you haven't tried Disk Utility on the drive to verify/repair it, I would do so.

...If you're using Mountain Lion, all bets are off.

Hope this helps.