Difference between revisions of "Redhat - fedora service startup"

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== run levels ==
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Service start and stop scrips are associated with run levels 0-6.  Each has a corresponding directory in /etc/rc.d.  For each run level, a script beginning with K stops the service, whereas a script beginning with S starts the service.
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== starting services on boot ==
 
== starting services on boot ==
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  # systemctl -a
 
  # systemctl -a
  
== Alternative method ==
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== chkconfig method ==
  
example:
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  # '''chkconfig sshd on '''/etc/systemd/system/
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===listing existing services===
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listing existing services and the run level start configurations
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# chkconfig --list
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example:  
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# chkconfig --list | grep sshd
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sshd            0:off  1:off  2:on    3:on    4:on    5:on    6:off
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corresponding start/stop scripts
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# grep -r -m 1 sshd /etc/rc.d/*  | sort -n
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/etc/rc.d/init.d/sshd:# processname: sshd
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/etc/rc.d/rc0.d/K25sshd:# processname: sshd
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/etc/rc.d/rc1.d/K25sshd:# processname: sshd
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/etc/rc.d/rc2.d/S55sshd:# processname: sshd
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/etc/rc.d/rc3.d/S55sshd:# processname: sshd
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/etc/rc.d/rc4.d/S55sshd:# processname: sshd
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/etc/rc.d/rc5.d/S55sshd:# processname: sshd
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/etc/rc.d/rc6.d/K25sshd:# processname: sshd
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===adding new services===
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adding a new service if isn't already listed. 
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  # '''chkconfig --add <name>'''
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name = service name as its start script appears in /etc/init.d/ or you will get an error
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example
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# '''chkconfig --add snmpd'''
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error reading information on service badserviced: Invalid argument
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example...
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# '''chkconfig --add snmpd'''
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check service just added, notice all run levels will be off by default
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# '''chkconfig --list | grep nrpe'''
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nrpe            0:off  1:off  2:off  3:off  4:off  5:off  6:off
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===setting the run levels===
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# chkconfig --level <levels> <name> on
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example, setting levels 2-5...
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# '''chkconfig --level 2345 snmpd on'''
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==misc info==
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# '''chkconfig sshd on
 
on fedora 17, the above command creates a symlink in a subdir of /etc/systemd/system/
 
on fedora 17, the above command creates a symlink in a subdir of /etc/systemd/system/
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[[category:redhat]]
 
[[category:redhat]]

Latest revision as of 16:31, 13 October 2014

Contents

run levels

Service start and stop scrips are associated with run levels 0-6. Each has a corresponding directory in /etc/rc.d. For each run level, a script beginning with K stops the service, whereas a script beginning with S starts the service.


starting services on boot

In order to start it automatically on every system boot, run

# systemctl enable sshd.service

Likewise, you can remove it from system startup

# systemctl disable sshd.service

If you would like to see a list of all available managed services, run

# systemctl -a

chkconfig method

listing existing services

listing existing services and the run level start configurations

# chkconfig --list

example:

# chkconfig --list | grep sshd
sshd            0:off   1:off   2:on    3:on    4:on    5:on    6:off

corresponding start/stop scripts

# grep -r -m 1 sshd /etc/rc.d/*  | sort -n
/etc/rc.d/init.d/sshd:# processname: sshd
/etc/rc.d/rc0.d/K25sshd:# processname: sshd
/etc/rc.d/rc1.d/K25sshd:# processname: sshd
/etc/rc.d/rc2.d/S55sshd:# processname: sshd
/etc/rc.d/rc3.d/S55sshd:# processname: sshd
/etc/rc.d/rc4.d/S55sshd:# processname: sshd
/etc/rc.d/rc5.d/S55sshd:# processname: sshd
/etc/rc.d/rc6.d/K25sshd:# processname: sshd

adding new services

adding a new service if isn't already listed.


# chkconfig --add <name>

name = service name as its start script appears in /etc/init.d/ or you will get an error

example

# chkconfig --add snmpd
error reading information on service badserviced: Invalid argument

example...

# chkconfig --add snmpd

check service just added, notice all run levels will be off by default

# chkconfig --list | grep nrpe
nrpe            0:off   1:off   2:off   3:off   4:off   5:off   6:off

setting the run levels

# chkconfig --level <levels> <name> on

example, setting levels 2-5...

# chkconfig --level 2345 snmpd on

misc info

# chkconfig sshd on 

on fedora 17, the above command creates a symlink in a subdir of /etc/systemd/system/