Linux 124 Lesson 8, managing local Linux users and groups, controlling services, and daemons

1. System startup and server Process Manager
RH5 6 Start the init process first System V

RH7 using SYSTEMD is the manager of the system startup and server processes
Characteristics:
parallelization function, 10-process parallel boot
Start the daemon on demand; just start the process you have to
Automatic service dependency, which can prevent long time-outs;
Control group, to realize the control mode of the process;

Systemctl SYSTEMD Unit
Unit type: 1,. Service Unit
2,. Socket sockets
3.. path Path Unit
4, ...
　　
Systemctl List-units manages various management units
　　
Systemctl status Ssh.service View the state of the corresponding service
　　
Type of Service status:
Active (running) is being passed one or more
Active (exited) has completed a one-time configuration
Active (waiting) running, waiting for event
Inactive (dead) is not in the running state
Fail Service failed to run
　　
The configuration file for the loaded unit has been processed
Enable the server to start automatically the next time it is powered on
Disable the service does not start automatically the next time it is powered on
Static cannot be enabled, but can be started by another unit
　　
Systemctl List-units manages various management units
Systemctl--type Service List all services
Systemctl status Sshd.service view sshd server Status
Systemctl is-active sshd.service Query service is active
Systemctl is-enabled sshd.service Query service is booting up
Systemctl--failed--type Service lists all services that failed to start

2. Control system Service
Start Service Systemctl start Sshd.service

Close Service Systemctl Stop Sshd.service

(3) Disable service Systemctl mask Iptables.service
Systemctl unmask Iptables.service
　　
(4) Boot start service Systemctl enabled Sshd.service
Turn off auto-start service systemctl disable Sshd.service
　　
(5) Restart service Systemctl Restart Sshd.service

Practice:
Start the PSACCT service;
Configure the PSACCT service to start at system startup
Stop Rsyslog Service
Configure the Rsyslog service so that it does not start at system startup
When done, perform scoring scripts for lab services Gradee

Linux 124 Lesson 8, managing local Linux users and groups, controlling services, and daemons