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This article mainly introduces the "introduction of common system services under CentOS and related shutdown methods". In daily operation, I believe that many people have doubts about the introduction of common system services and related shutdown methods under CentOS. Xiaobian consulted all kinds of materials and sorted out simple and easy-to-use operation methods. I hope it will be helpful to answer the doubts of "introduction of common system services and related shutdown methods under CentOS". Next, please follow the editor to study!

Common system service items

Apmd some notebooks and old hardware use apmd. If your computer supports acpi, you should turn off apmd.

If acpi is supported, then acpi will do the work of apmd

NetworkManager automatically converts among multiple network connections

Acpid new power management standard, usually used by notebook computers

Anacron

Automate running task daemons

Atd

Automate running task daemons

Auditd audit information, which stores the system audit records generated by the kernel

Autofs automatically installs the management process automount

Avahi-daemon Zeroconf service discovery daemon

Avahi-dnsconfd / etc/avahi/dnsconf.action script daemon

Bluetooth Bluetooth

Conman console Management

Cpuspeed monitors the percentage of idle system, reduces or speeds up the CPU clock speed and voltage on

Crond automatically schedule tasks to start

Cups generic UNIX print daemon

Dnsmasq Dns cache server daemon

Dund Bluetooth Dial-up Network

User configuration wizard after firstboot installation for setting up the system for the first time

Gpm terminal to provide mouse support (no graphical interface) copy, paste and so on. Can be turned on and off under the graphical interface

Haldaemon hardware monitoring system

Hidd Bluetooth H.I.D. Server

Httpd Apache server

Ip6tables ipv6 tables firewall daemon

Ipmi OpenIPMI Driver initialization script

Iptables iptables firewall daemon

Irda infrared port daemon

Load balancing of system interrupt requests in irqbalance multi-system processor environment, single CPU is useless

Kdump initialization kdump script

Kudzu hardware automatic detection program, if you do not add new hardware, you can close

Lvm2-monitor LVM2 mirror devices daemon

Mcstrans SELinux Context Translation System Daemon

Daemons for mdmonitor RAID-related devices

Daemons for mdmpd RAID-related devices

Messagebus event monitoring service, which starts by sending broadcast messages to all users if necessary

Microcode_ctl can encode and send new microcode to the kernel to update the Intel IA32 series processor daemon

Multipathd Manage device-mapper multipath devices

Netconsole Initializes network console logging

Netfs installs and uninstalls NFS, SAMBA, and NCP network file systems

The netplugd service monitors the web interface, shuts it down or starts it according to the signal, and is used on laptops

Network activates the script with configured network interface to open

Nfs network file system daemon

Nfslock NFS file locking function

Nscd password and Group search Service

Ntpd network time synchronization

Oddjobd

Pand Bluetooth personal area Network

Pcscd smart card support

Portmap is used to support RPC connections, and RPC is used for services such as NFS and NIS

Psacct process audit daemon

Rawdevices rawdevices to block devices . Oracle database usage

Rdisc discovers routers daemon

Readahead_early boot memory loading optimization

Readahead_later boot memory loading optimization

Associated with restorecond SELinux

Rpcgssd manages RPCSEC GSS contexts for the NFSv4 server

Rpcidmapd for NFSv4 that maps user names to UID and GID numbers

Rpcsvcgssd manages RPCSEC GSS contexts for the NFSv4 server

Saslauthd uses SASL's authentication daemon

Sendmail mail server sendmail daemon

Setroubleshoot SELinux Troubleshooting

Smartd Monitoring hard disk failure

Sshd OpenSSH server daemon

Syslog Syslog

Tcsd TrouSerS server daemon

Winbind is used for Samba server

Wpa_supplicant wireless device support

Xfs X Window font server daemon, which provides font sets for local and remote X servers

Ypbind activates the ypbind service process for NIS clients

Automatic upgrade of yum-updatesd RPM operating system and package management daemon

Shut down the system service

In order to use the system to run faster and more smoothly, ML turns on some services by default. But if you don't use these services, they will waste your valuable system resources, and you can choose to turn them off or disable them. Shut down unwanted services: ntsysv then close the service name appropriately according to the entries listed below, or modify it directly according to the following instructions:

If there is no printer:

The code is as follows:

/ sbin/chkconfig-- level 235 cups off

If there is no local area network:

The code is as follows:

/ sbin/chkconfig-- level 235 smb off

If the remote user login is not required:

The code is as follows:

/ sbin/chkconfig-- level 235 sshd off

If you don't need a timed task:

The code is as follows:

/ sbin/chkconfig-- level 235 crond off

If you do not need to add new hardware:

The code is as follows:

/ sbin/chkconfig-- level 235 kudzu off

Tips on knowledge points:

The code is as follows:

Chkconfig

Function description: command to activate and shut down services, check and set up various services of the system.

Syntax:

The code is as follows:

Chkconfig [--add] [--del] [--list] [system Services]

Chkconfig [--level] [system Services] [on/off/reset]

Related commands:

The code is as follows:

Ntsysv runlevel telinit

This instruction is a program developed by Redhat in accordance with GPL rules. It can query which system services, including various background programs, will be executed by the operating system at each execution level (runlevel).

Linux os divides the operating environment into the following seven levels:

0: power on (please do not switch to this level)

1: text interface in single user mode.

2: the text interface of multi-user mode does not have the function of network file system (NFS).

3: multi-user mode text interface, with network file system (NFS) function.

4: some distributions of linux use this level to enter x windows system.

5: some distributions of linux use this level to enter x windows system.

6: restart.

Parameters:

-- add adds specified system services

-- del deletes the specified system service

-- list lists all system services and level codes that can currently be managed from the chkconfig directive

-- level specifies the execution level in which the system service should be turned on or off

On/off/reset registers at the specified execution and turns on / off / resets the system service.

Example:

1. View the status of services at different levels of execution:

The code is as follows:

$chkconfig-list

two。 List the startup of the system service apmd at each execution level:

The code is as follows:

$chkconfig-list apmd

3. At execution level 2p3, 5, shut down the apmd system service:

The code is as follows:

$chkconfig-- level 235 apmd off

4. Turn on the apmd system service at execution level 2, 3, 5:

The code is as follows:

$chkconfig-- level 235 apmd on

At this point, the study on "introduction of common system services and related shutdown methods under CentOS" is over. I hope to be able to solve your doubts. The collocation of theory and practice can better help you learn, go and try it! If you want to continue to learn more related knowledge, please continue to follow the website, the editor will continue to work hard to bring you more practical articles!

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