how to add into sudoers user
how to setup sudo for a user - echo /etc/sudoers.d/user01 >> user01 ALL=(ALL) ALL
you can do like this....OR
in the file user20 ALL=(ALL) NOPASSWD:ALL
usermod -aG wheel user
visudo --> %wheel ALL=(ALL) ALL
how to add the sudoers group and give access - To enable sudo access to the group named gourp01
echo /etc/sudoers.d/group01 >> %group01 ALL=(ALL) AL
configuring password ageing - chage command will do this: m=maximum, W warning, I inactivity
1- force user to change the password on the next login
2- display the information about user
3- expire account on 2-2-2020
4-command to expire the account and lock the command in same command.
5- asign no login shell
6- change the password policy for the consultant account to require a new pass every 15 days
7-Set the passwords to expire 180 days from the current date for all users. Use administrative rights to
edit the configuration file.
8- The chown command can also be used to change group ownership of a file by preceding the group
name with a colon (:). For example, the following command changes the group test_dir to admins:
9-The chown command can also be used to change both owner and group at the same time
10- how to unlock the user - 1- chage -d 0 user01
2- chage -l user01
3- i- # date -d "+45 days" +%F
ii # chage -E 2020-10-01 user01
,4- chage -L -e 2019-0-05 user01
5- usermod -s /sbin/nologin user01
6- chage -M 15 consultant
7-Set PASS_MAX_DAYS to 180in/etc/login.defs. Use administrative rights when opening the file with the
text editor. You can use the sudo vim /etc/login.defs command to perform this step.
8-chown :admins test_dir
9-chown visitor:guests test_dir
#chown owner.group filename
10- usermod -U <username>
1- how to zip a directory
2- how to tar the folder
3- how to uncompress .tar file
4-by bzip2 compress the file anme testfile
5-unzip bzip2 file - 1- tar -zcvf archive.tar.gz /folder
2- tar -cvf archive.tar.gz /foler
3- tar -xvf archine.tar.gz
4- bzip2 testfile
5- bzip2 -d
virtual machine activity :
1- how to list the vm
2- stop start the vm
3- check the information about the vm, storage and other information. - 1- virsh list --all
2-virsh start centos7.0
3- virsh edit centos7.0
on client command to mount nfs - mount -t nfs <ipaddressofthenfs.server>:/nfs /mnt/nfs
, on client command to mount smb - mount -t cifs //ip/share /mnt/smb -o username=xyz,password=bvr
find grub to boot in a different kernel - grubby --info=ALL
set grubby to index 5 - grubby --set-default-index=5
verify the boot grubby - grubby --default-index
logical volume create command - lvcreate -n <name> -L 3G <name vgroup>
volume group command - vgcreate <>vgname> /dev/sdc /dev/sdb
extend the partition - lvextend -L +200M /dev/RHCSA/pinehead
show link statistics
how to check the routes
trace path - ip -s link show ens3
ip route /ip -6 route
tracepath access.redhat.com
Troubleshooting ports - ss -ta
ss -la
add ip nmcli - sudo nmcli con add con-name "static-addr" ifname enX \
type ethernet ipv4.method manual \
ipv4.address 172.25.250.10/24 ipv4.gateway 172.25.250.254
modify the ip address - nmcli