A common cause of sudden failure.
WHAT HAPPENS
A job produces output every run.
If directed to a file, that file grows continuously.
If emailed, mail accumulates in a mailbox.
THE SYMPTOM
Disk usage rising steadily Eventually, an account at its limit and everything failing
THE MAIL VERSION
A job running every fifteen minutes emails you ninety-six times a day.
That mailbox fills, and if it is your main address you stop noticing real mail.
WHAT TO DO
While testing, keep output on so you can see problems Once working, suppress output or direct it to a rotated log
REDIRECTING TO A LOG
Useful, and clear or rotate it.
An unrotated log grows indefinitely.
CHECKING
Look at your disk usage by directory.
A large log file in your home directory is frequently the cause of an unexplained disk problem.
WHAT TO CHECK MONTHLY
Any log files your cron jobs produce.
