Showing posts with label linux system config services. Show all posts
Showing posts with label linux system config services. Show all posts

Tuesday, September 20, 2011

Linux SYSTEM SERVICES DAEMONS

Linux SYSTEM SERVICES DAEMONS
The system services can be classified into 2 types: /etc/xinetd.d based & /etc/rc.d/init.d based services.
/etc/xinetd.d --based services are

telnet finger imap ipop2 ipop3
pop3s rlogin rsh sgi_fam
the executable daemons of these services are at /etc/rc.d/init.d, named xinetd

/etc/rc.d/init.d – based services are
apmd autofs dhcpd halt httpd
iptables kudzu named network nfs
portmap sendmail snmpd smb ssh
squid vncserver vsftpd xinetd ypbind
ypserv zebra

 apmd automatic power management daemon
 autofs automatic file system
 dhcpd dynamic host configuring protocol daemon
 httpd hyper text transfer protocol daemon
 iptables for fire wall security
 kudzu enabling plug and play facility
 named for bind (DNS-Domain Name System) server
 nfs network file system
 portmap services that starts when n/w is enabled
 sendmail used for mail server application
 snmpd simple n/w management protocol
 smb samba server (Linux/windows connectivity)
 ssh secure shell daemon
 squid proxy server
 vncserver remote desktop sharing
 vsftpd very secure file transfer protocol daemon
 xinetd enable /etc/xinetd.d services
 ypbind NIS(n/w info server) client
 ypserv NIS server
 zebra used for routing.

Ways of enabling these services:-
chkconfig enabling a service this way keeps a service enabled until next restart.
#chkconfig - -list service_name displays the current run level of that service.
#chkconfig service_name on/off used to enable/disable a particular service
#chkconfig - -levels 35 service_name on enables that service on run levels 3,5

Run control script resides in /etc/rc.d contains script files for rc0 to rc6. [the script file starting with ‘S’ represents the scripts to be start-up during next system boot and the script starting with K represents the stopped scripts].

#ntsysv cmnd used to enable or disable a service during next start up too.

Enable Services

#/etc/rc.d/init.d/service-name start/stop/restart/reload/status
OR
#service service-name start/stop/restart/reload/status

Configuring a YUM Repository
-------------------------------

Steps:

Make sure ftp server package is selected while installing the m/c in which we are planning to create a yum repository.

Copy all rpms from the corresponding directory on RHEL DVD to somewhere under /var/ftp/ say /var/ftp/pub/Server

install createrepo rpm which is inside the rhel dvd

#createrepo /var/ftp/pub/Server

that's all yum repository is ready to use.

To make it available for other machines in the network via ftp

#/etc/init.d/vsftpd start
#chkconfig vsftpd on

On client machines
let our yum repository is available at 192.168.0.254

#cd /etc/yum.repos.d/
#cat > test.repo
[first repo]
name= my first repo
baseurl=ftp://192.168.0.254/pub/Server
enabled=1
gpgcheck=0

ctrl+c

#yum list all

To check whether a package is installed or not

#rpm -qa | grep -i

To install something using YUM

#yum install

/etc more tremcap
Etc less termcap
Find -name
Find -perm 700
Find - uid 500
Find –size

Ln -s --------soft link
Ln ----------hard link

Umask –S | umask in symbolic form
Find –print | grep xorg.conf

Environmental Variables $PATH $DISPLAY $PS1 $TERM $USER $HOME $SHELL

Set command shows all the variables

PATH=$PATH:/root

Linux SYSTEM SERVICES DAEMONS

Linux SYSTEM SERVICES DAEMONS
The system services can be classified into 2 types: /etc/xinetd.d based & /etc/rc.d/init.d based services.
/etc/xinetd.d --based services are

telnet finger imap ipop2 ipop3
pop3s rlogin rsh sgi_fam
the executable daemons of these services are at /etc/rc.d/init.d, named xinetd

/etc/rc.d/init.d – based services are
apmd autofs dhcpd halt httpd
iptables kudzu named network nfs
portmap sendmail snmpd smb ssh
squid vncserver vsftpd xinetd ypbind
ypserv zebra

 apmd automatic power management daemon
 autofs automatic file system
 dhcpd dynamic host configuring protocol daemon
 httpd hyper text transfer protocol daemon
 iptables for fire wall security
 kudzu enabling plug and play facility
 named for bind (DNS-Domain Name System) server
 nfs network file system
 portmap services that starts when n/w is enabled
 sendmail used for mail server application
 snmpd simple n/w management protocol
 smb samba server (Linux/windows connectivity)
 ssh secure shell daemon
 squid proxy server
 vncserver remote desktop sharing
 vsftpd very secure file transfer protocol daemon
 xinetd enable /etc/xinetd.d services
 ypbind NIS(n/w info server) client
 ypserv NIS server
 zebra used for routing.

Ways of enabling these services:-
chkconfig enabling a service this way keeps a service enabled until next restart.
#chkconfig - -list service_name displays the current run level of that service.
#chkconfig service_name on/off used to enable/disable a particular service
#chkconfig - -levels 35 service_name on enables that service on run levels 3,5

Run control script resides in /etc/rc.d contains script files for rc0 to rc6. [the script file starting with ‘S’ represents the scripts to be start-up during next system boot and the script starting with K represents the stopped scripts].

#ntsysv cmnd used to enable or disable a service during next start up too.

Enable Services

#/etc/rc.d/init.d/service-name start/stop/restart/reload/status
OR
#service service-name start/stop/restart/reload/status

Configuring a YUM Repository
-------------------------------

Steps:

Make sure ftp server package is selected while installing the m/c in which we are planning to create a yum repository.

Copy all rpms from the corresponding directory on RHEL DVD to somewhere under /var/ftp/ say /var/ftp/pub/Server

install createrepo rpm which is inside the rhel dvd

#createrepo /var/ftp/pub/Server

that's all yum repository is ready to use.

To make it available for other machines in the network via ftp

#/etc/init.d/vsftpd start
#chkconfig vsftpd on

On client machines
let our yum repository is available at 192.168.0.254

#cd /etc/yum.repos.d/
#cat > test.repo
[first repo]
name= my first repo
baseurl=ftp://192.168.0.254/pub/Server
enabled=1
gpgcheck=0

ctrl+c

#yum list all

To check whether a package is installed or not

#rpm -qa | grep -i

To install something using YUM

#yum install

/etc more tremcap
Etc less termcap
Find -name
Find -perm 700
Find - uid 500
Find –size

Ln -s --------soft link
Ln ----------hard link

Umask –S | umask in symbolic form
Find –print | grep xorg.conf

Environmental Variables $PATH $DISPLAY $PS1 $TERM $USER $HOME $SHELL

Set command shows all the variables

PATH=$PATH:/root