trunk/cronie/crontabs.4

.TH CRONTABS 4 2012-08-29 "Marcela Mašláňová" "Crontabs users' Manual"
.SH NAME
crontabs \- configuration and scripts for running periodical jobs
.SH SYNOPSIS
.B run-parts 
.RB [ --list | --test ] \fP\fI<directory>\fP
.br
.SH DESCRIPTION
Crontabs is a historical name for the run-parts script and the system
crontab. The run-parts script runs all executables in the specified
directory.
.B Run-parts
runs all executables in the specified directory.
The execution of files can be allowed or denied by creating file 
.B jobs.allow
or 
.B jobs.deny
which worked similar as other allow/deny config files. The file must be
created in the specified directory.
.TP
.B --list
print names of all files (not limited to executables), but don't run
them. This option can't be used with 
.B test
option.
.TP
.B --test
print names of files, which would be run.

Randomization of jobs can be configured in the 
.IR /etc/sysconfig/run-parts
file. To enable randomization of jobs, set the RANDOMIZE parameter to 1
and set the RANDOM parameter to an integer which determines a random
seed. Additionally, you may configure the RANDOMTIME parameter (again,
by specifying an integer) to provide an additional level of
randomization. Jobs are not randomized when the RANDOM and RANDOMTIME
parameters are set to 0. Values in these two parameters must be set to
1 or larger to provide a good enough randomization.

Randomization of cron jobs can be useful for shared networks, where
multiple cron jobs executed at once can cause spikes in traffic,
especially during daily jobs. With randomized jobs, the workload is
evenly distributed throughout the day.

.SH EXAMPLE OF CONFIGURATION FILE
.nf
RANDOMIZE=1
RANDOM=4
RANDOMTIME=8
.fi
.PP
Historically the crontab file contained configuration which called 
.B run-parts
on files in 
.I cron.{daily,weekly,monthly}
directories. These jobs are now run
indirectly through 
.B anacron 
to prevent conflicts between 
.B cron 
and 
.B anacron.
That means the 
.B anacron 
package has to be installed if the jobs in these
directories should be running. Refer to the 
.B anacron(8) 
how to limit the time of day of the job execution.

.SH EXAMPLE
.I /etc/cron.daily/jobs.deny
could contain for example 
.B 0logwatch 
which forbid execution of this script.
.SH "SEE ALSO"
.B anacron(8), crontab(5)
1	niro	2172	.TH CRONTABS 4 2012-08-29 "Marcela Mašláňová" "Crontabs users' Manual"
2			.SH NAME
3			crontabs \- configuration and scripts for running periodical jobs
4			.SH SYNOPSIS
5			.B run-parts
6			.RB [ --list \| --test ] \fP\fI<directory>\fP
7			.br
8			.SH DESCRIPTION
9			Crontabs is a historical name for the run-parts script and the system
10			crontab. The run-parts script runs all executables in the specified
11			directory.
12			.B Run-parts
13			runs all executables in the specified directory.
14			The execution of files can be allowed or denied by creating file
15			.B jobs.allow
16			or
17			.B jobs.deny
18			which worked similar as other allow/deny config files. The file must be
19			created in the specified directory.
20			.TP
21			.B --list
22			print names of all files (not limited to executables), but don't run
23			them. This option can't be used with
24			.B test
25			option.
26			.TP
27			.B --test
28			print names of files, which would be run.
29
30			Randomization of jobs can be configured in the
31			.IR /etc/sysconfig/run-parts
32			file. To enable randomization of jobs, set the RANDOMIZE parameter to 1
33			and set the RANDOM parameter to an integer which determines a random
34			seed. Additionally, you may configure the RANDOMTIME parameter (again,
35			by specifying an integer) to provide an additional level of
36			randomization. Jobs are not randomized when the RANDOM and RANDOMTIME
37			parameters are set to 0. Values in these two parameters must be set to
38			1 or larger to provide a good enough randomization.
39
40			Randomization of cron jobs can be useful for shared networks, where
41			multiple cron jobs executed at once can cause spikes in traffic,
42			especially during daily jobs. With randomized jobs, the workload is
43			evenly distributed throughout the day.
44
45			.SH EXAMPLE OF CONFIGURATION FILE
46			.nf
47			RANDOMIZE=1
48			RANDOM=4
49			RANDOMTIME=8
50			.fi
51			.PP
52			Historically the crontab file contained configuration which called
53			.B run-parts
54			on files in
55			.I cron.{daily,weekly,monthly}
56			directories. These jobs are now run
57			indirectly through
58			.B anacron
59			to prevent conflicts between
60			.B cron
61			and
62			.B anacron.
63			That means the
64			.B anacron
65			package has to be installed if the jobs in these
66			directories should be running. Refer to the
67			.B anacron(8)
68			how to limit the time of day of the job execution.
69
70			.SH EXAMPLE
71			.I /etc/cron.daily/jobs.deny
72			could contain for example
73			.B 0logwatch
74			which forbid execution of this script.
75			.SH "SEE ALSO"
76			.B anacron(8), crontab(5)