Key services for CentOS optimization to be started

1. run the setup command to set the key services for starting the system: enter Systemservices to set the corresponding startup service. remove the preceding * directly if you do not need. Ps: Introduction five important services: sshd: SSH is a reliable protocol designed for remote login sessions and other network services, while sshd is a server. Rsyslog: Rsyslog is a self-generated

1. use the setup command to set the key services for startup:

 

Enter System services to set the corresponding boot service. remove the previous * directly without any need.

Ps: Introduction to five important services:

Sshd: SSH is a reliable protocol that provides security for remote logon sessions and other network services. sshd is the server side.

Rsyslog: Rsyslog is a free software, GPL lincesed enhanced syslogd. It supports MySQL and fully configurable output formats (including large timestamps. Rsyslog initiates Rainer's gehatts. Collect data from the standard sysklogd package. The rsyslog project aims to provide a more reliable system log daemon process and configuration. The so-called "reliability" refers to the support for TCP or RFC 3195 (reliable system logs) reliable transmission mode. This does not mean that the sysklogd package is unreliable.

Network: linux network configuration

Crond:Set the periodically executed command. This command reads commands from the standard input device and stores them in the crontab file for later reading and execution.

Systat:Sysstat is a software package that includes a set of tools to monitor system performance and efficiency. these tools collect system performance data for us, such as CPU usage, hard disk and network throughput data, the collection and analysis of these data helps us determine whether the system is operating normally. it is a good assistant to improve the system operation efficiency and run the server safely.

 

2. chkconfig: the chkconfig command is used to update (start or stop) and query system service running level information.

The opening status and current running level of system services at each running level are displayed:

A. Use the chkconfig command to query the system services that are enabled at the running level of 3.

 

B. use the chkconfig command to view and disable the atd system service.

 

C. use the combination of chkconfig and awk to disable system services other than sshd, network, syslog, crond, and sysstat in batches.

 

① Use the combination of chkconfig and awk to retrieve the first column of the system service:

 

② Use the combination of chkconfig and awk to disable them in batches:

Solution 1:

 

Solution 2:

 

3. enable the atd service with the running level of 456 at the same time: