Startup Disk Memory Inexplicably Low/Missing

Question

I normally keep a close eye on the amount of info going into my partitioned Mac HD (presently: capacity 29.88 GB, 27.64 Used, 2.23 Available), but I received a message today to the effect that "your startup disk is low in available memory..." while only running Safari... The last time I had checked (about 1 month ago) I had between 9 and 10 GB of available space, so needless to say I was rather surprised to get this message. I immediately did a "Get Info" on the drive and was SHOCKED for TWO reasons! 1) that the available memory was so low... but ALSO as I checked and RE-checked the memory was DISAPPEARING before my eyes! I was only running Safari (although a couple hours prior I had worked on and saved a 5+ page site in iWeb with a fair amount of imagery... I have 1 GB of RAM. I restarted and the drive has since stabalized at 2.22-2.23 GB Available. I restarted in Safe Mode and restarted again and ran a repair permissions on it. All seems to be ok for now BUT I haven't reopened iWeb for fear that that may be eating up what little memory is left AND then there is this OTHER issue of where these other 8 or so GB have gone to???? When I calculate Finder items in the HD they total 19.5 GB not the 27.64 that "Get Info" pulls up for it. One more note: I installed iLife '06 about a month ago... What is happening here?
PowerBook G4 17"   Mac OS X (10.4.5)  

Answer 1

Hi, O.
1. IMO, with only 2-3 GB of available (free) space, you're critically short of free disk space. Cache files and virtual memory swap files could readily and quickly consume that. See my "Problems from insufficient RAM and free hard disk space" FAQ.
2. A runaway process constantly writing to log files can chew up disk space. Check these Console logs for clues, specifically large blocks of repeating messages that recur at high-frequency. If you find such blocks, post some samples for diagnosis. Again, do not post the entire log or logs, just copy/paste samples of blocks of repeating messages that recur at high frequency.
Common causes of runaway processes writing to logs include software associated with Canon and HP scanners, software for HP All-In-One devices, and Adobe Acrobat version 7.x prior to version 7.0.5. Depending on the messages you post, I can give you specific actions to take if one of those apply.
3. See also my "Freeing Space on your Mac OS X startup disk" FAQ.
Good luck!
Dr. Smoke
Author: Troubleshooting Mac® OS X
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