This last week I've noticed that our family server was was responding very slowly. Some investigating turned up a rampage logd process that was gobbling up 40-80% of my poor old G4's CPU. Killing the process did no good, it just respawned. Turning off Timemachine (a known culprit of rogue logd processes) didn't help either. A look at the console turned up the true culprit: Mozy.
My Mozy log is absolutely full of errors like this:
2008-10-12 16:24:01.804 Mozy[223:5c33] ERR (churn) DirectoryIterator: PathNode is not a directory /Users/alex/Pictures
Dozens of of those entries per second. No wonder logd is choking.
A first glance at my Mozy configuration didn't show an obvious file configuration problem. Based on the error I assumed that I had an alias to my pictures directory that Mozy was choking on for some reason. Unfortunately unchecking the aliases didn't solve the problem, but did bring up a new problem: the backup configuration was listed as containing 0 files/0 kb.
At this point I figured I just had a configuration problem of some kind and so reinstalled Mozy. Sadly, no love. After some digging I discovered the true problem "Backup Sets." Since I don't use the backup sets (I use File & Folders configuration exclusively), I'd disregarded them. Even when none of them are actually being used, Mozy still polls the backup sets for files to be backed up. To find those files the sets look for specific types of files in specific directories. One of those, was the pictures directory. Problem was that directory didn't actually exist anymore. I'd changed all of the folders in my home directory to be aliases pointing to an external drive. Mozy didn't follow the alias (presumably to avoid infinite loops, which is what I had initially guessed was the actual problem) and so just knew that a directory it was searching for pictures wasn't actually a directory at all.
After deleting a few backup sets (I actually deleted them all), and rebooting everything is peachy. Mozy is happy and logd is behaving. Problem solved.