Linux tutorial RHCSA/LPIC1

  User Administration in Linux Syntax: useradd <username> Configuration File: /etc/passwd User Administration with customization Syntax: useradd <option> <argument> <username> Options: u - UID g - GID c - Comment d - home directory b - base directory -e account expiry  -o non unique -G make member of secondary group -r system user -s user login shell User modification  Syntax: usermod <option> <argument> <username> Options: u - UID g - GID c - Comment d - home directory b - base directory -e account expiry  -o non unique -G make member of secondary group -r system user -s user login shell User password management Syntax: passwd <username>                 chpasswd Configuration file: /etc/shadow   Group Administration Syntax: groupadd <groupname> Configuration file: /etc/groups User account delete and group delete Syntax:  userdel  -r  <userna...

   There are seven types of files in linux. - Regular File d directory b block device file c character device file s socket file p pipe file l link file Assigning permission Syntax: chmod  (u/g/o/a)  (+/-/=) (r/w/x/-)  <file name/path> u - user g -group o - others a - all r read w write x execute + add permission - remove permission = assign permission Permission using numbers 4 read 2 write 1 execute Changing ownership Syntax: chown <username>:<groupname> <file / directory name> Access control list setfacl -m u:<username>:<permission>  <file name> sefacl -x  u:<username> <file name> getfacl <file name/directory>   Special permissions suid sgid sticky bit

  Logical Volume Management  Steps in LVM creation A. Partition Creation 1. Create Physical Partition using fdisk command # fdisk <disk name>  2. Create physical volume # pvcreate <physical partition name 1> <physical partition name 2> .. n #pvs and # pvdisplay above command used to display pv. 3. Create volume group #vgcreate  <vg name>  <pv name1>  <pv name 2> #vgdisplay # vgs 4. Create logical Volume  # lvcreate -L <size> -n <lvname> <vgname>  #lvdisplay # lvs B. Format Partition #mkfs.<file system> <lv path> # mkfs -t <file system> <lv path> for swap mkswap <lvpath> C. Mount Partition a. temporary b. permanent  Steps to delete partition 1. Unmount 2.Delete LVM partition 3.Delete Volume group 4.Delete Physical volume 5.Delete Physical partition

  Types of Partition  There are three types of partition in linux.      A.Primary Partition     B.Extended Partition     C.Logical Partition We can create three primary partition and one extended partition.And 60 logical partition on extented one. Total number of partition is 64 on one disk. Syntax: fdisk <disk name> m for help Options: n - add new partition p - list partition table d - delete partition w - save partition t - toggle change system ID Some important commands used for partition # fdisk -l  list partition table # lsblk list disk and disk partition # blkid display block id of partition with file system # df -hT  disk consumption with human readable form

  What is yum utility in linux? yum is a open source package manager for linux os and its allows automatically update and dependency management. yum stands for yellow dog update and modifier. Syntax: yum <option> <package name> Options: install - to install single or multiple packages groupinstall - install group of packages update - update single or multiple packages remove - uninstall package info - display detail info about package list - list install packages clear - clear cache repolist - display list of all repositories

  What is Package manager in redhat/centos?  RPM stands for redhat package manager, RPM is default package manager in redhat/centos systems. What is package? Package is a bundle of programs lwhich is to be installed on any OS. For redhat/centos : .rpm For debian/ubuntu: .deb For windows;  .exe For mac: .pkg Syntax: rpm  <option>  <package name> Options: q - query     qi - display detail info about specific packages     ql - list files of packages     qd - list document own by packages     qa - list all installaed packages     qc - list configuration file of packages i - install package     v - verbose     h - human readable e - erase V - verify U - upgrade install package    

  How to set hostname in linux? Syntax: # hostnamectl set-hostname <hostname>                # echo <hostname>  > /etc/hostname How to check and  assing IP to server in linux? To check IP of system # ip a # ip addr show Through Graphical Console # nmtui  Through CLI # nmcli If command not found then try to install package  NetworkManager and NetworkManager-tui IP allocation using ifconfig utility

  What is booting process? Basically how system starts and we get GUI is called as booting process. 1.BIOS/UEFS BIOS is a Basic input and output system. UEFS is a unified extensible firmware.  2. Master Boot Loader It has the total size of 512 kb.     446 kb for boot loader     64  kb for partition table     2 kb for future reserved 3. Boot Loaders Boot loader in RHEL8 and RHEL9 is grub2. It has location of kernal. GRUB2 is stand for Grand Unified Boot Loader. 4.Kernal   Kernal loads in system and take command of systems. 5.Systemd This is the first process of linux system. 6.Targets Simply target means user console(GUI/CLI)