9, System guidance, service management, process management

1. System Boot

RunLevel viewing current levels

N 5 n No level 5 current level

Modify/etc/inittab//comment off restart health INITQ effective immediately

linux7 Default Run Level

0 Turn off the machine

1 stand-alone user mode

Multi-user mode with 2-character interface (network not supported)

3. Multi-user mode for character interface

4. Not assigned to use

5. Multi-user mode for graphical interface

6. Restart

Liunx Guided Overview

1. Boot boot

Host power-on self-test, load Bols hardware information

Read the MBR's boot file (Grub,lilo)

Booting the Linux kernel

Run the first process init (process number is always 1)

Go to the appropriate operating level

Run terminal, enter user name and password

2.init process and configuration files

The execution/sbin/init program is loaded, and the process ID is always 1.

Master configuration file/etc/inittab

18 Line: Id:5:initdefault:

32 Line: Ctrlaltdel

I'm going to hit an init q to get him into effect immediately.

3. Init script

/etc/rc.d/rc.syinit System Initialization

/ETC/RC.D/RC Specifies the run level, loading terminates the corresponding system service

/etc/rc.d/rc.local Boot Autorun Script

S for Level 1 n represents the last time no level

File syntax

[Set Project]:[runlevel]:[init action Behavior]:[Command Project]

Set up a project: up to 4 characters, representing the init work item, simple description

Operation level join: 0123456

Init operation:

Initdefault Indicates the default boot level

Sysinit initialization operation

Ctrlaltdel three-kin restart

Wait g indicates that the subsequent item must be completed before proceeding

Respawn indicates that the following init is the active reboot

2. System Service Control

Standalone Service startup method

Service AutoFS status//view AutoFS service running state

Service AutoFS//hit Enter to view Help parameters

Service AutoFS restart//Restart services

Stop//Stop start//start Relolad/Reload

Standalone service hand using absolute path start-up service

/etc/init.d/autofs

/etc/init.d/xxx/start/stop/restart/status

Service XXX Start/stop/restart/status

Auto Start service

Chkconfig--list | Less or/etc/init.d/*//lists the self-starting status of all services

Chkconfig--list sshd//View the startup level of the SSHD service

Chkconfig--level 5 sshd on//specify level to start service

Chkconfig--level 5 sshd off//specified level shutdown service

or Chkconfig--level CAPI on//Set 3 and 5 level self-booting

or chkconfig CAPI on//set 2345 auto Start

NTSYSV//default setting of the self-service at the current level

NTSYSV--level 35//default setting of self-service in 3 and 5 levels

Temporary services

/etc/rc.d/init.d///Standalone service path

/etc/xinetd.d///Temporary Services

PS View the shell used by the current system

PS aux process Management//a display current all processes u in user-oriented format output x displays all processes for the current user

Ps-e

Ps-elf//e Display all processes in the system L long format display F full format display

Stat Status R is running S sleep State Z zombie State

Top//view process TOP-D5//change every five seconds by default three seconds

Enter top press Shift+p to sort the CPU in reverse order by shirt+m in reverse memory

T in descending order according to the time consumed K kills the specified process

Pstree//Display in tree form

PSTREE-AUP//-a displays the full command line-u lists the user names that each process belongs to-p lists the corresponding PID numbers

Pstree-p WSYHT//View the process tree for a specified user

After the command that starts the program, add a & to indicate that the program is running in the background

CTRL + Z key//suspend current process (pause and move to background)

Jobs//View background Task List, when no ordinal is specified, the default value is the most recent task

FG//Restore the background task to the foreground, when no ordinal is specified, the default value is the most recent task

BG//Activate background is suspended task, when no ordinal is specified, the default value is the most recent task

-9 Forced Delete

PS aux | grep QQ View has not opened QQ process

Pgrep-l "Log"//Add an L output process name, not just ID, query has not opened log process

Pgrep-l-u wsyht//query Wsyht All processes opened by the user

Kill 23619//Kill a single process, delete with process number

Killall QQ or Pkill QQ//Kill single process, delete with process name

Pkill-9-U wsyht//force kick-out user

This article is from the "Wsyht blog" blog, make sure to keep this source http://wsyht2015.blog.51cto.com/9014030/1790252

9, System guidance, service management, process management