Chris,
Our HISTORY files on each of our Condor nodes is getting large. Is
there some way to safely truncate and archive this file without
shutting down a daemon, or configure it to be done automatically?
You can just "mv" it to a new name, a new file will be created.
What I do is keep a hard link to "history" named "history.YYYYMM".
At the start of the month I can simply delete "history". In this case
I also create a new "history" myself so I can make a new hard link.
I do this automatically with a cron job:
0 0 1 * * cd /exports/condor/spool && rm history && touch history && ln history $(date +history.\%Y\%m)