unix and linux system administration handbook

Common Linux System administration commandsWhoAmI shows the user of the current operation, such as:650) this.width=650; "src=" Http://p3.pstatp.com/large/19210001778d80f7b8c8 "alt=" Linux Learning ~linux System

includes a file system of size 0 blocks -B,--block-size= size block with specified -H,--human-readable file system size in an easy-to-understand format (e.g. 1K 234M 2G) -H,--si similar to-H, but takes 1000 of the time instead of 1024 -I,--inodes displays inode information instead of block usage -K is--block-size=1k -L,--local only displays the native file

(1) Process management1. Determine the server health status2. View the processA. Viewing all processes in the system: PSExample: PS aux (using BSD OS command format)A show all foreground processesX Show all background processesU shows which user generatedPs-le (using the Linux Standard command format)-L display more detailed information-E Show All processesResult descriptionVSZ: Occupies virtual memory size

simply enters the command man and the name of the command shell will list a complete description.Standard usage:Name of the man commandTo query the description page of the LS command, enter the command: Man lsTo flip through the manual page, you can use the page UP and PAGE DOWN keys, or use the spacebar to turn back one page and use B to flip forward. To exit the manual page, enter the command Q. To search for keywords in the manuals page, enter a command/and keyword or phrase to search for, a

example: useradd-d/home/bird bird2 ---bird2 is the account name,/home/Bird is the main directory of Bird2 -the general user of the system's main directory is generally built in/home/this pathpasswd Set User password -- in Linux, Superuser can use the passwd command to set or modify the user's password for a normal user. Users can also use the command directly to modify their own passwords without having to use the user name after the command. --pa

also useful when creating a RAM disk.Module classLsmodDegree of importance: MediumLists all installed kernel modules.InsmodDegree of importance: MediumForce the installation of a kernel module (instead of using modprobe if possible) must be called as root.RmmodDegree of importance: MediumForces the uninstallation of a kernel module. Must be called as root.ModprobeDegree of importance: MediumThe module loader, in general, is automatically called in the startup script. Must be called as root.Depm

80/tcpBased on C/S modelLoading httpd/var/www/html/ETC/HTTPD/CONF/HTTPD.CONF Master configuration fileSELinuxAn access model developed by the U.S. Security ServiceEnableDisabledEnforing: Mandatory mode if our actions violate selinux, force a refusalPermissive: If you violate SELinux, you will only be warned that you can still accessFiles can be set up with permissions called DAC active access controlSELinux mac for files or directories, mandatory access controlTwo important elements related to S

Stat Displays details of the specified file, more detailed than LSWho shows online loginWHOAMI Show current Operation userHostname Display host nameUname Display System InformationTop dynamic display currently consumes the most resources process informationPS Display transient process status Ps-auxDu view directory size Du-h/home with units display directory informationDF View disk size df-h with unit display disk informationIfconfig Viewing network c

Cd Ls Pwd Clear chmod Chown Chattr Useradd Userdel Groupadd Vi/vim Cat More Less Mv Cp Rm RmDir Touch Ifconfig IP addr Ping Route Echo Wc Expr Bc ln Head Tail W.H.O. Hostname Top Df Du Netstat Ss Kill Alias Mans Tar Zip Unzip Jar Fdisk Free Uptime Lsof Lsmod Lsattr Dd Date Crontab Ps Find Awd Sed Grep Sort Uniq Service:DhcpSambaDnsApacheMysqlNginxZabixSquidVarnishLvsKeepalivedEL

Linux File System administration commandsCommon Commands1. DF command to view the usage of the partitionCommon options-H More Humane-m displays partition usage in megabytesDisplay information:Mounted on: Mount pointFilesystem: The specific hardware name that corresponds to2, du command to view the file/directory size, by default in K unitsCommon options:-H "Human

: Modify which NIC to follow which, only one can be omitted) x.x.x.x/y (M.M.M.M)//modify IP information; x:ip address, Y: Mask length, M: mask. such as =225.225.255.0Shutdown-h now or Poweroff or init 0//shutdown operation.Shutdown-r now or reboot or init 6//restart operation.Shutdown-r +15 ' The system would be rebboted!! '//Send a notification to each user who is currently logged on to the Linux host ' th

Some basic commands for system administration commandsAPMD Advanced Power Management (APMD command is responsible for BIOS Advanced Power Management (APM) related records, warnings, and administrative work)APMD "Options" "percent change" "percent value"-P "percent change" when the magnitude of the power change exceeds the set percentage change, the event is logged-U sets the BIOS clock to UTC-V Logs all APM

systems on nodes and disk blocks. Options meaning -A Show disk usage for all file systems -M Display in 1024-byte units -T Displays disk space usage for each specified file system -T Display file system Detecting the disk space occupied by the catalog: DuThe du command is used to count th

Chapter 23rd UNIX File SystemNamed pipe Mkfifo:mkfifo [-M mode] pipe. Named pipes must be created explicitly and will not disappear (the RM command can be removed).The proc file is a pseudo-file used to access kernel information. For example, if a process ID is 1952, the process-related information can be found in a file in the/proc/1952 directory.The VFS (virtual file system) implements the details of file

1:unix file Type-3 typesNormal files (regular files): Text files (plain text, scripts, source programs, configuration files, HTML, etc.), binary files (multimedia files, databases, etc.)Directories: for organizing filesPseudo-file: does not store data for the purpose of providing a service. Divided into three kinds:Special files: Device drivers, file representations of physical devices (keyboards, monitors, etc.)Named pipes: Directing the output of on

[Linux Unix -- exec and fock System Call], linux operating system If you have any shortcomings, please kindly advise. Reprinted Please note: @ CSU-Max Series of blog posts: Linux and Unix