"Startup disk almost full" message

[mwrobison]

I had a similar problem over the weekend. I thought I'd post here just to help out anyone else who has my problem (disk full, USB backup).

I've been using SuperDuper for over two years now with no problems whatsoever. Currently, I'm backing up to a disk (WD 500GB USB) attached to my Airport Extreme (I'm connected to the Airport via hard wiring, not wirelessly) using the smart update function to a sparse image. It usually functions just fine, but Saturday when doing the scheduled backup, the USB drive turned off for some reason. This caused two errors:

1. My source disk filled up completely. Every last KB. When looking around to find the massive file eating up the space, nothing was there (~95GB worth of space disappeared).
2. Whenever I booted into OS X (10.4.11), the Airport Disk Utility gave me a message saying that the Airport Disk had turned on and to connect, please enter my password. However when I entered the password, it would not connect, and I could not get the USB drive to mount. Airport Utility found the disk just fine, but I couldn't mount it.

The solution to both problems was exactly what Dave describes above. Using the Finder "Go To" function, I went to "/Volumes", found the FOLDER with the same name as my backup drive, deleted that folder, emptied the trash, and robooted. Everything came up just fine, hard disk space was back, and the error with the Airport Disk was gone. I assume that OS was having a conflict the the actual USB drive and the folder in the "Volumes" directory being named the same thing, thus the mounting issues.

Anyway, thanks to Dave for posting about this problem already, and for a great product.