Rhcsa Exam Model Question

RHCSA EXAM MODEL QUESTION

BY SARAVANAN.C (919688798896)

To Display Exam Question ➔

Crack root password

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Set hostname

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Set IP Address

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yum repo

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SELinux Enforcing

Cracking root password use ctl+alt+del in send keys tab in virtual server m/c when grub displays press tab key to freeze .Press e to edit grub

new password: confirm password: sh] touch /autorelabel

search for Linux16 string and press end key and add this line exit

rd.break console=tty press ctl+x to save and restart #root: mount -o remount,rw /sysroot #chroot /sysroot/ sh] passwd

exit

Setting hostname Setting hostname #hostname (or) #cat /etc/hostname displays the current hostname Change host temporarily #host newhostname change host permanently #hostctl set-hostname newhostname

Setting hostname using nmtui #nmtui

Setting IP Address Using nmcli

Activate connection

Setting IP

#nmcli device status

#nmcli connection up con-name

Can be in 3 ways

adding connection

Restart network

#nmcli connection.add con-name as ifname etho type ethernet ip4 172.25.7.0 gw4 172.25.0.0

#systemctl restart network

● ● ●

Network Manager (GUI) nmcli nmtui

To check set dns

Using Network Manager

#ifconfig #nmcli connection modify as ip4.dns 172.25.6.8

Go to right top where network manager icon and set ip,dns and gateway address from the question

manual assign

Using nmtui

#nmcli connection modify as ip4.method manual

#nmtui

Set auto connect

Set the values for ip,dns,gateway

#nmcli connection modify as connection. autoconnect yes

#cat /etc/resolv.conf

Setting yum repo and SElinux Setting yum repo #cd /etc/yum.repos.d/ #vim myown.repo [myown] baseurl=”paste the url from the question” enabled=1 gpgcheck=0 :wq #yum clean all #yum repolist all #yum install any package to check if its installing from our own repo

Set SELinux Permission #vim /etc/sysconfig/selinux change the line selinux=premissive to selinux=enforcing :wq #getenforce

1 . swap partition #fdisk -l

:n

#fdisk /dev/vda

default(first sector)

P - print the list of pratitions

default(last sector) +100M

n - create new partition

t

e or p (extended or primary)

l: 82 ( linux swap type)

:e

:p (to print the partitions)

default(first sector)

:w (to save the changes)

default(last sector)

#partprobe (intimate to kernel)

#mkswap /dev/vda2 #mkdir /test #vim /etc/fstab /dev/vda2 /test swap swap defaults 0 0 #swapon -a #mount -a #df -h /dev/vda2 /test

100M

2 . user, group creation with permissions User creation with UID

# date -d “+1month”

Setting permission for file or folder

#useradd -u 2323 ashwin

# usermod -e YYYY-MM-DD ashwin

#chmod u-x,g-x,o-x /file or /folder

#passwd ashwin

or # chage -E YYYY-MM-DD ashwin

removes execute permission to all

#cat /etc/passwd

# chage -l ashwin

#setfacl -m u:ashwin: 0 /file or /folder/

User creation with no login shell

Group creation and adding user

removes read/write for user ashwin

#useradd -s /bin/nologin kaviya

#groudadd sysmanager

#chmod g+rwx,o= /file or folder

#passwd kaviya

#chgrp sysmanager ashwin

others dont have permission to read,write

#su - kayiva

Adding to user when creating user

#chmod g+s /file or folder

Not allowed

#useradd -G sysmanager ashwin

files will be created in group ownership automatically

3 . Crontab Set cronjon for user to /bin/echo string at h:m

Deny Cron for specific user

#crontab -e -u username

#vim /etc/cron.deny

m h * * * /bin/echo "string"

ashwin

#systemctl restart crond.service #su - username

#crontab -e -u ashwin

#mail

This program is not allowed

4 . find grep copy command combined & collaborative directory

Creating Collaborative directory Locate files of user and copy to to some path #mkdir -p /a/b #find / -user ashwin -exec cp -a {}/file path \; #chgrp sysmanager /a/b Note: If path doesnt exists create using mkdir #chmod g+rw,o= /a/b Find string in all file and copy to some path #grep "string" /source > /destination path

or #chmod 770 /a/b sets read,write to group sysmanger and other no permission to access /a/b #chmod g+s /a/b sets group permission automatically when files created in that directory

5 . LDAP Autofs

Setting LDAP #yum install authconfig-gtk* ssd* krb5* -y #authconfig-gtk

#yum install autofs* -y #systemctl restart autofs #systemctl enable autofs #vim /etc/auto.master

Set all the values from question /rhome /etc/auto.misc

#getent passwd ldauserx( x denotes station number) You can see details about ldapuserx

#vim /etc/auto.misc ldapuserx -rw,sync,nfvers=3 servername:/rhome/ldapuserx #systemctl restart autofs #systemctl enable autofs #su - ldapuserx #ls

#cd ldapuserx

6 . LVM LVM reduce

LVM Increase

#lvdisplay

#lvdisplay

#vim /etc/fstab

#vim /etc/fstab

#umount /dev/vgname/vo

#umount /dev/vgname

#e2fsck -f /dev/vgname/vo

#e2fsck -f /dev/vgname

#resize2fs -p* /dev/vgname/vo 120M

#lvextend -L 120M /dev/vgname

#lvreduce -L 120M /dev/vgname/vo

#resize2fs -p /dev/

#mount /dev/vgname

#mount /dev/vgname

#lvdisplay

#lvdisplay

#df -h

#df -h

7 . LVM creation Convert volume to filesystem Creating physical volume

#fdisk -l

:n

#pvcreate /dev/vdb4

#fdisk /dev/vda

default(first sector)

Creating volume group

P - print the list of pratitions

default(last sector) +100M

n - create new partition

t

e or p (extended or primary)

l: 83 ( linux LVM type)

#lvcreate -l 35 -n volname /dev/mapper/vgname

:e

:p (to print the partitions)

Display volume

default(first sector)

:w (to save the changes)

#lvdisplay

default(last sector)

#partprobe (intimate to kernel)

#mkfs.ext3 /dev/mapper/vgnanme/volna me

#mkfs.vfat /dev/mapper/vgname/volnam #vgcreate -s 8M vgname /dev/vdb4 e Creating volume

Create directory to mount #mkdir /lvm

Add entry to fstab #/dev/mapper/vgname /lvm ext3 defaults 0 0 :wq Refresh using mount #mount -a List the mounted directory #df -h

8 . Kernel update ,compression & NTP service

Kernel Update download the file from the given url using ezlink #rpm -vh package name #reboot NTP Service #vim /etc/chrony.conf add the source url given the question for NTP

Compression methods: tar #tar -cvf /destionationpath/filename.tar /source path bz2 #tar -cvjf /destionationpath/filename.bz2 /source path gz #tar -cvzf /destionationpath/filename.gz /source path xz #tar -cvJf /destionationpath/filename.xz /source path

Problem in booting due to wrong entry in /etc/fstab Booting in emergency target:

use ctl+alt+del in send keys tab in virtual server m/c when grub displays press tab key to freeze .Press e to edit grub search for Linux16 string and press end key and add this line systemd.unit =emergency.target use ctl+x to save and reboot #root: mount -o remount,rw / #vim /etct/fstab remove the wrong entry and save using :wq

#reboot