My sites, MagazineFrames.Com and ComicFrames.com have been working merrily for several months. Until today. I got an email from a buyer saying that he couldn't complete an order. When he went to view his cart he got a message saying there was nothing in his cart. I can't sell much that way. Checking into it I discovered that other things such as my admin pages that rely on session variables wern't working either. None of my session variables were working for anything.
After much testing, debugging, looking at all my php params and restarting the server a couple of times, I discovered that all the session files were being written with zero length. No disk space left even though my ISP's reports showed that I had 150 meg left out of 500. After cleaning out some log files I was back in business. My ISP has been promising some log file tools for the last couple of months and I had been waiting on them. No more waiting. I have root access so tonight I start my working on my own scripts for log file cleanup.
I add this for future searches in case anyone else happens to be as dumb as I and ignores their log files.