After upgrading to 10.5, I noticed that the load on the machine was considerably higher than usual (the 'load average' is roughly the number of processes waiting for CPU time). I had assumed that this was mostly because of the new Time Machine backups I had turned on on the machine.
In an effort to reduce the machine's load, I turned off Spotlight indexing which seemed to help some. The load was still a bit higher than what was previously normal, though.
Eventually, I discovered that the new _mailman user conflicted with the mailman user I had created when installing the mailman mailing list software on the machine a while ago:
% sudo dscl . -read users/mailman RecordName
RecordName: _mailman mailman
Of course, the _mailman account had a UID/GID of 78, while the account I had created had a UID/GID of 504.
I could not determine how to correct this with dscl, since it showed a 'merged' version of both accounts, and instead just removed the mailman.plist from /var/db/dslocal/nodes/Default/users. I then rebooted (as sending SIGHUP to DirectoryServices didn't seem to get it to pick up the changes I had just made).
The load on the machine went down to 'normal' levels then, and I decided to re-enable spotlight. After it finished indexing the drive, the load on the geeklair seems to have stabilized back at the old levels.
Update: I ended up disabling spotlight again (while leaving Time Machine active) as the backups are useful, but command-line mdfind doesn't get used very much (if at all).
