freebsd-dev/libexec/atrun/atrun.man
Mateusz Guzik e61e6189e5 atrun(8): scale default load average limit with the number of CPUs
Previously atrun refused to run jobs if load average was not below fixed limit of 1.5.

PR:		173175
Reviewed by:	peterj
Approved by:	trasz (mentor)
MFC after:	2 weeks
2012-10-30 19:46:00 +00:00

83 lines
1.6 KiB
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.\" $FreeBSD$
.Dd October 30, 2012
.Dt ATRUN 8
.Os
.Sh NAME
.Nm atrun
.Nd run jobs queued for later execution
.Sh SYNOPSIS
.Nm atrun
.Op Fl l Ar load_avg
.Op Fl d
.Sh DESCRIPTION
.Nm Atrun
runs jobs queued by
.Xr at 1 .
.Pp
Root's
.Xr crontab 5
file
.Pa /etc/crontab
has to contain the line
.Bd -literal
*/5 * * * * root /usr/libexec/atrun
.Ed
.Pp
so that
.Nm
gets invoked every five minutes.
.Pp
At every invocation,
.Nm
will start all the jobs in the lowercase queues whose start
time has elapsed.
In addition, if the load average over the last minute was less than
the specified limit then a maximum of one batch job (denoted by the
uppercase queues) is started.
.Pp
Before starting a job,
.Nm
will check the status of its owner's account with
.Xr pam 3
and refuse to run the job if the account is unavailable,
e.g., locked out or expired.
.Sh OPTIONS
.Bl -tag -width indent
.It Fl l Ar load_avg
Specify a limiting load factor, over which batch jobs should
not be run, instead of the default of 1.5 * number of active CPUs.
.It Fl d
Debug; print error messages to standard error instead of using
.Xr syslog 3 .
.El
.Sh WARNINGS
For
.Nm
to work, you have to start up a
.Xr cron 8
daemon.
.Sh FILES
.Bl -tag -width /etc/pam.d/atrun -compact
.It Pa /etc/pam.d/atrun
.Xr pam.conf 5
configuration file for
.Nm
.It Pa /var/at/jobs
Directory containing job files
.It Pa /var/at/spool
Directory containing output spool files
.El
.Sh SEE ALSO
.Xr at 1 ,
.Xr crontab 1 ,
.Xr pam 3 ,
.Xr syslog 3 ,
.Xr crontab 5 ,
.Xr pam.conf 5 ,
.Xr cron 8
.Sh BUGS
The functionality of
.Nm
should be merged into
.Xr cron 8 .