Rhcsa Road

The first day
Install the virtual machine and RHEL The requirements of ：

1. Do not install security software

2. Make sure window 64 position Not educational

file system （ A method and data structure for organizing files on disk ） ntfs ---- The maximum number of single files supported is 4TB fat32 ---- The largest single file supported is 4G

3. Enable virtual machine prompt VT-X Did not open ( The physical machine does not have virtualization enabled )

Environment deployment system installation ：

Virtual platform （vmware-workstation）+ Create a virtual machine +RHEL-server-8.5-x86_64.iso（ Image file ）

( Network mode selection - Host only nat* The bridge ; Disk type ide sata scsi nvme*)

Log in to the main user name and password to verify

linux System administrator Default root user ----- The later Login Host logs in through the administrator

Ordinary users redhat

Log in as Administrator —— After creating an account , On the login screen , Click on the not listed ?, User name is root, The password was created before .

Be careful ： Judge whether the command is successful , The first method returns to the next command prompt without any prompt The second type has corresponding command result prompt

Pay attention to the meaning of version number ——

1.0～2.6 Previous version :A.B.C

RHEL8.2

A-- Major version number with significant changes ; 

B-- Minor version number with some major modifications

C-- It refers to the amendment number with minor revision ,C Development version for odd numbers , Even numbers are stable

1. Look at the host ip Address

command —— ifconfig perhaps ip a

#ip   a ==ip addr
2: ens160: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 00:0c:29:c3:cf:a9 brd ff:ff:ff:ff:ff:ff
    inet 192.168.220.162/24 brd 192.168.220.255 scope global dynamic ens160
       valid_lft 1710sec preferred_lft 1710sec

notes ： use xshell Connect Linux—— stay xshell Internal input ssh+ host ip, for example ssh 192.168.10. 129, You can connect it ip The address is 192.168.10.129 The host

2. terminal （ Standard input and output devices keyboard, mouse, display ）

command ——  tty   View the device file of the current terminal

Virtual terminal ：ctrl+alt+F3 ~ F6 ctrl +alt+F2 /dev/tty3 /dev/tty4

Analog terminal ： Graphical simulation of the terminal window

Remote terminal ： Pseudo terminal Terminal window based on remote connection through remote software /dev/pts/0 /dev/pts/1 ...

Physical terminals

3. The command prompt of the terminal

[[email protected] ~]#
user name @ Host name    current path ~ The tag is when the user's home directory /root   # Tag manager
notes ： Catalog ----window Folder
[[email protected] ~]$ pwd     （print   workdoing  directory   Print current directory path ）
/home/redhat
redhat  ~ The mark is   /home/redhat     $ Mark ordinary users

4. The standard format of the command

1.# command       #ifconfig
2.# command     Parameters    #ip   a
3.# command    - Options ...   #ls  -l   #ls -a
4.# command    - Options ...   Parameters     #ls -l   /root
                -l   Short options
                --long Long options

5. Basic commands

#ip a    see ip Address 
#ifconfig  see ip Address 
#tty    View the device file name of the current terminal 
#cat /etc/redhat-realse   View operating system release information 
#uname -r     View kernel version 
#pwd  Show current directory path 
#hostname  View the current full hostname 
#hostname   HOSTNAME    Temporarily change the host name while the current host is running . After changing the host name of the terminal prompt device, you need to exit and log in again 
#hostnamectl set-hostname  HOSTNAME          vim  /etc/hostname    Change host name permanently 
#passwd  [USERNAME]    Change or set the user's password 
#passwd -d  [USERNAME]   Delete user password 

 notes ：
 Management execution passwd：    You can specify a user name ; Don't enter the previous password ; You can change and delete the passwords of all users ; There are no strict requirements for password level 
 Common user execution passwd：  You cannot access the specified user name. You can only change your own password ; You need to enter the previous password ;  There are strict requirements for password registration 

6. System password reset

1. Restart the client 
2. Quickly click the mouse in the startup interface and click the up and down buttons to switch （ Stay in the startup interface ）+e
3. find linux Add... At the end of the line at the beginning of the line ------rd.break------ crtl + x  -------   mount   -o   remount,rw    /sysroot   ----chroot   /sysroot     -----passwd root ----touch /.autorelabel ---exit   ---exit