The load average of a system, as displayed by the uptime and
w commands, represents the average number of processes that are queued
to run on the CPUs or CPU cores over a given time period. Typically, a system might not
considered overloaded until the load average exceeds 0.8 times the number of CPUs or CPU
cores. On such systems, you would usually want atd
to be able to run
batch jobs when the load average drops below the number of CPUs or CPU cores, rather than
the default limit of 0.8. For example, on a system with 4 CPU cores, you could set the
load-average limit above which atd
will not run batch jobs to 3.2.
If you know that a batch job typically takes more than a minute to run, you can also
change the minimum interval that atd
waits between starting batch jobs.
The default minimum interval is 60 seconds.
To change the load-average limit and minimum interval time for batch jobs:
Edit the
atd
configuration file,/etc/sysconfig/atd
, uncomment the line that defines theOPTS
variable, and edit the line to specify the new load-average limit and minimum interval time, for example:OPTS="-b 100 -l 3"
This example sets the minimum interval to 100 seconds and the load-average limit to 3.
Restart the
atd
service:#
systemctl restart atd
Verify that the
atd
daemon is running with the new minimum interval and load-average limit:#
systemctl status atd
atd.service - Job spooling tools Loaded: loaded (/usr/lib/systemd/system/atd.service; enabled) Active: active (running) since Mon 2014-04-28 15:37:04 BST; 2min 53s ago Main PID: 6731 (atd) CGroup: /system.slice/atd.service └─6731 /usr/sbin/atd -f -b 100 -l 3 Apr 28 15:37:04 localhost.localdomain systemd[1]: Started Job spooling tools.
For more information, see the systemctl(1)
and
atd(8)
manual pages.