The software described in this documentation is either in Extended Support or Sustaining Support. See https://www.oracle.com/us/support/library/enterprise-linux-support-policies-069172.pdf for more information.
Oracle recommends that you upgrade the software described by this documentation as soon as possible.
System anacron jobs are defined in
/etc/anacrontab, which contains definitions for
the SHELL, PATH,
MAILTO, RANDOM_DELAY, and
START_HOURS_RANGE variables for the environment
in which the jobs run, followed by the job definitions themselves.
Comment lines start with a # character.
RANDOM_DELAY is the maximum number of random
time in minutes that anacron adds to the
delay parameter for a job. The default
minimum delay is 6 minutes. The random offset is intended to
prevent anacron overloading the system with too
many jobs at the same time.
START_HOURS_RANGE is the time range of hours
during the day when anacron can run scheduled jobs.
Job definitions are specified in the following format:
period delay job-id commandwhere the fields are:
-
period Frequency of job execution specified in days or as
@daily,@weekly, or@monthlyfor once per day, week, or month.-
delay Number of minutes to wait before running a job.
-
job-id Unique name for the job in log files.
-
command The shell script or command to be run.
The following entries are taken from the default
/etc/anacrontab file:
SHELL=/bin/sh PATH=/sbin:/bin:/usr/sbin:/usr/bin MAILTO=root # the maximal random delay added to the base delay of the jobs RANDOM_DELAY=45 # the jobs will be started during the following hours only START_HOURS_RANGE=3-22 #period in days delay in minutes job-identifier command 1 5 cron.daily nice run-parts /etc/cron.daily 7 25 cron.weekly nice run-parts /etc/cron.weekly @monthly 45 cron.monthly nice run-parts /etc/cron.monthly
By default, anacron runs jobs between 03:00 and
22:00 and randomly delays jobs by between 11 and 50 minutes. The
job scripts in /etc/cron.daily, run anywhere
between 03:11 and 03:50 every day if the system is running, or
after the system is booted and the time is less than 22:00. The
run-parts script sequentially executes every
program within the directory specified as its argument.
Scripts in /etc/cron.weekly run once per week
with a delay offset of between 31 and 70 minutes.
Scripts in /etc/cron.monthly run once per week
with a delay offset of between 51 and 90 minutes.
For more information, see the anacron(8) and
anacrontab(5) manual pages.