EX200 Sample Questions Answers

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[root@node1 ~]# cat /etc/passwd | grep nologin > /root/strings

[root@node1 ~]# cat /root/strings

bin:x:1:1:bin:/bin:/sbin/nologin

daemon:x:2:2:daemon:/sbin:/sbin/nologin

adm:x:3:4:adm:/var/adm:/sbin/nologin

lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin

mail:x:8:12:mail:/var/spool/mail:/sbin/nologin

# which echo

# crontab -e

23 14 * * * /bin/echo hello

# crontab -l (Verify)

1. Use fdisk /dev/hda-> To create new partition.

2. Type n ->For New partitions

3. It will ask for Logical or Primary Partitions. Press l for logical.

4. It will ask for the Starting Cylinder: Use the Default by pressing Enter

Keys

5. Type the size: +100M you can specify either Last cylinder of size here.

6. Press P to verify the partitions lists and remember the partitions name.

7. Press w to write on partitions table.

8. Either Reboot or use partprobe command.

9. Use mkfs -t ext3 /dev/hda?

OR

1. mke2fs -j /dev/hda? ->To create ext3 filesystem.

2. vi /etc/fstab

3. Write:

/dev/hda? /data ext3 defaults 0 0

4. Verify by mounting on current sessions also:

mount /dev/hda? /data

• rpm -ivh ftp://server1/example.com/pub/updates/zsh-*

or

• Login to ftp server : ftp ftp://server1.example.com using anonymous user.
• Change the directory: cd pub and cd updates
• Download the package: mget zsh-*
• Quit from the ftp prompt : bye
• Install the package
• rpm -ivh zsh-*
• Verify either package is installed or not : rpm -q zsh

lvextend -L 190M /dev/mapper/vgsrv-common resize2fs /dev/mapper/vgsrv-common

# cd /etc/syscofig/network-scripts/

# ls

# vim ifcfg-eth0 (Configure IP Address, Gateway and DNS) IPADDR=172.24.40.40

GATEWAY=172.24.40.1

DNS1=172.24.40.1

# vim /etc/sysconfig/network

(Configure Host Name)

HOSTNAME= station.domain40.example.com

OR

Graphical Interfaces:

System->Preference->Network Connections (Configure IP Address, Gateway and DNS) Vim /etc/sysconfig/network

(Configure Host Name)

By default, system accept the logs only generated from local host. To accept the Log from other host configure:

vi /etc/sysconfig/syslog SYSLOGD_OPTIONS="-m 0 -r"

Where

-m 0 disables 'MARK' messages.

-r enables logging from remote machines

-x disables DNS lookups on messages received with -r

service syslog restart

fdisk -cu /dev/vda// in the way of expanding the partition, don’t make main partition

partx –a /dev/vda

mkswap /dev/vdax

swapon /dev/vdax

swapon –s

vi /etc/fstab

/dev/vdaxswapswapdefaults0 0

mount -a

# cat /etc/testfile | while read line;

do

echo $line | grep abcde | tee -a /tmp/testfile

done

OR

grep `abcde' /etc/testfile > /tmp/testfile

# fdisk /dev/sda

p

(check Partition table)

n

(create new partition: press e to create extended partition, press p to create the main partition, and the extended partition is further divided into logical partitions) Enter

+2G

t

l

W

partx -a /dev/sda

partprobe

mkswap /dev/sda8

Copy UUID

swapon -a

vim /etc/fstab

UUID=XXXXX swap swap defaults 0 0

(swapon -s)

(1)find /etc -size 10k -exec cp {} /tmp/findfiles \;

(2)find / -user lucy -exec cp -a {} /tmp/findfiles \;

Note: If find users and permissions, you need to use cp - a options, to keep file permissions and user attributes etc.

• if=/dev/zero of=/swapfile bs=1M count=600 mkswap /swapfile

/etc/fstab:

/swapfile swap swap defaults 0 0 mount -a

• vi /etc/sysconfig/network GATEWAY=192.168.0.254

OR

vi /etc/sysconf/network-scripts/ifcfg-eth0 DEVICE=eth0

BOOTPROTO=static

ONBOOT=yes

IPADDR=192.168.0.?

NETMASK=255.255.255.0

GATEWAY=192.168.0.254

• service network restart

Gateway defines the way to exit the packets. According to question System working as a router for two networks have IP Address 192.168.0.254 and 192.168.1.254.

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[root@node1 ~]# cp -p /etc/fstab /var/tmp/

[root@node1 ~]# ls -lrt /etc/fstab

[root@node1 ~]# ls -lrt /var/tmp/fstab

[root@node1 ~]# chmod a+x /var/tmp/fstab

[root@node1 ~]# getfacl /var/tmp/fstab

[root@node1 ~]# setfacl -m u:harry:rw- /var/tmp/fstab

[root@node1 ~]# setfacl -m u:natasha:--- /var/tmp/fstab

[root@node1 ~]# getfacl /var/tmp/fstab

getfacl: Removing leading '/' from absolute path names

# file: var/tmp/fstab

# owner: root

# group: root

user::rwx

user:harry:rw-

user:natasha:---

group::r-x

mask::rwx

other::r-x

*

[root@node1 ~]# su - natasha

[natasha@node1 ~]$ cat /var/tmp/fstab

cat: /var/tmp/fstab: Permission denied

• cp -a /etc/fstab /var/tmp
• cd /var/tmp
• ls -l
• getfacl /var/tmp/fstab
• chmod ugo-x /var/tmp/fstab

[ No need to do this, there won't be execute permission for the file by default]

# setfacl -m u:natasha:rw /var/tmp/fstab # setfacl -m u:harry:0 /var/tmp/fstab(zero)

[Read permission will be there for all the users, by default. Check it using ls -l /var/tmp/fstab] Verify by

[ ls -la /var/tmp/fstab]

* [root@node1 ~]# groupadd sharegrp

[root@node1 ~]# useradd harry

[root@node1 ~]# useradd natasha

[root@node1 ~]# usermod -aG sharegrp harry

[root@node1 ~]# usermod -aG sharegrp natasha

[root@node1 ~]# useradd -s /sbin/nologin copper

[root@node1 ~]# echo "redhat" | passwd --stdin harry

[root@node1 ~]# echo "redhat" | passwd --stdin natasha

[root@node1 ~]# echo "redhat" | passwd --stdin copper

### For Checking ###

[root@node1 ~]# su - copper

This account is currently not available.

[root@node1 ~]# su - natasha

[root@node1 ~]# id

[root@node1 ~]# su - harry

[root@node1 ~]# id

• groupadd sysmgrs
• useradd -G sysmgrs Natasha

• We can verify the newly created user by cat /etc/passwd)

# useradd -G sysmgrs harry

# useradd -s /sbin/nologin sarrh

# passwd Natasha

# passwd harry

# passwd sarrah

below

• iptables -F
• service iptables save
• iptables -A INPUT -s 172.25.0.0/16 -j REJECT
• service iptables save
• service iptables restart

yum -y install sssd authconfig-gtk krb5-workstation authconfig-gtk // open the graphical interface

Modify user account database to ldap, fill up DN and LDAP SERVER as questions required, use TLS to encrypt connections making tick, write http://server.domain11.example.com/pub/EXAMPLE-CA-CERT to download ca, authentication method choose ldap password.

You can test if the ldapuser is added by the following command:

Id ldapuser1

Note: user password doesn’t not need to set

# cd /root; wget ftp://192.168.0.254/pub/boot.iso

# mkdir -p /media/cdrom

# vim /etc/fstab

/root/boot.iso /media/cdrom iso9660 defaults,loop 0 0

# mount -a

mount [-t vfstype] [-o options] device dir

# yum install -y httpd

# chkconfig httpd on

# cd /var/www/html

# wget http://ip/dir/example.html

# cp example.com index.html

# vim /etc/httpd/conf/httpd.conf

NameVirtualHost 192.168.0.254:80

DocumentRoot /var/www/html/

ServerName station.domain40.example.com

*

[root@node1 ~]# useradd -u 3945 fred

[root@node1 ~]# echo "iamredhatman" | passwd --stdin fred

Changing password for user fred.

passwd: all authentication tokens updated successfully

• fdisk -l
• fdisk -cu /dev/vda

p n

e or p select e

default (first): enter

default (last): enter n

default(first): enter

default(first): +754M t (1-5)

l: 82 p

w #reboot

#mkswap /dev/vda5

• vim /etc/fstab

/dev/vda5 swap swap defaults 0 0

wq

• mount -a
• swapon -a
• swapon -s

# fdisk

# partprobe

# pvcreate /dev/vda6

# vgcreate -s 8M vg1 /dev/vda6 -s

# lvcreate -n lvshare -l 50 vg1 -l

# mkfs.ext4 /dev/vg1/lvshare

# mkdir -p /mnt/data

# vim /etc/fstab

/dev/vg1/lvshare /mnt/data ext4 defaults 0 0

# mount -a

# df -h

Graphical Interfaces:

System-->Administration-->Date & Time

OR

# system-config-date

• vi /etc/httpd/conf.d/ssl.conf ServerName www.rhce.com DocumentRoot /var/www/rhce DirectoryIndex index.html index.htm ServerAdmin webmaster@rhce.com SSLEngine on SSLCertificateFile /etc/httpd/conf/ssl.crt/server.crt SSLCertificateKeyFile /etc/httpd/conf/ssl.key/server.key
• cd /etc/httpd/conf

3 make testcert

• Create the directory and index page on specified path. (Index page can download from ftp://server1.example.com at exam time)
• service httpd start|restart
• chkconfig httpd on

Apache can provide encrypted communications using SSL (Secure Socket Layer). To make use of encrypted communication, a client must request to https protocol, which is uses port 443. For HTTPS protocol required the certificate file and key file.

*

[shangrila@node1 ~]$ podman ps

CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES

d5ffe018a53c registry.domain15.example.com:5000/rhel8/rsyslog:latest /bin/rsyslog.sh 5 seconds ago Up 4 seconds ago logserver

[shangrila@node1 ~]$ podman stats logserver

Error: stats is not supported in rootless mode without cgroups v2

[shangrila@node1 ~]$ podman stop logserver

d5ffe018a53ca7eb075bf560d1f30822ab6fe51eba58fd1a8f370eda79806496

[shangrila@node1 ~]$ podman rm logserver

Error: no container with name or ID logserver found: no such container

[shangrila@node1 ~]$ mkdir -p container-journal/

*

[shangrila@node1 ~]$ sudo systemctl restart systemd-journald

[sudo] password for shangrila:

[shangrila@node1 ~]$ sudo cp -av /var/log/journal/* container-journal/

[shangrila@node1 ~]$ sudo cp -av /var/log/journal/* container-journal/

[shangrila@node1 ~]$ sudo chown -R shangrila container-journal/

[shangrila@node1 ~]$ podman run -d --name logserver -v /home/shangrila/container-journal/:/var/log/journal:Z registry.domain15.example.com:5000/rhel8/rsyslog

[shangrila@node1 ~]$ podman ps

[shangrila@node1 ~]$ loginctl enable-linger

[shangrila@node1 ~]$ loginctl show-user shangrila|grep -i linger

Linger=yes

*

[shangrila@node1 ~]$ podman stop logserver

[shangrila@node1 ~]$ podman rm logserver

[shangrila@node1 ~]$ systemctl --user daemon-reload

[shangrila@node1 ~]$ systemctl --user enable --now container-logserver

[shangrila@node1 ~]$ podman ps

CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES

3903e1d09170 registry.domain15.example.com:5000/rhel8/rsyslog:latest /bin/rsyslog.sh 4 seconds ago Up 4 seconds ago logserver

[shangrila@node1 ~]$ systemctl --user stop container-logserver.service

*

[shangrila@node1 ~]$ sudo reboot

[shangrila@node1 ~]$ podman ps -a

CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES

7e6cd59c506a registry.domain15.example.com:5000/rhel8/rsyslog:latest /bin/rsyslog.sh 10 seconds ago Up 9 seconds ago logserver

*

[root@node2 ~]# lsblk

NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT

vdb 252:16 0 5G 0 disk

└─vdb1 252:17 0 4.2G 0 part

└─vgrz-lvrz 253:2 0 4.1G 0 lvm /datarz

vdc 252:32 0 5G 0 disk

└─vdc1 252:33 0 4.4G 0 part

└─datavg-datalv 253:3 0 3.9G 0 lvm /data

vdd 252:48 0 5G 0 disk

vde 252:64 0 10G 0 disk

[root@node2 ~]# lvs

LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert

lvrz vgrz -wi-ao---- 4.10g

[root@node2 ~]# vgs

VG #PV #LV #SN Attr VSize VFree

vgrz 1 1 0 wz--n- <4.15g 48.00m

[root@node2 ~]# parted /dev/vdb print

Number Start End Size Type File system Flags

1 1049kB 4456MB 4455MB primary lvm

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[root@node2 ~]# df -hT

Filesystem Type Size Used Avail Use% Mounted on

/dev/mapper/vgrz-lvrz ext4 4.0G 17M 3.8G 1% /datarz

[root@node2 ~]# parted /dev/vdb mkpart primary 4456MiB 5100MiB

[root@node2 ~]# parted /dev/vdb set 2 lvm on

[root@node2 ~]# udevadm settle

[root@node2 ~]# pvcreate /dev/vdb2

Physical volume "/dev/vdb2" successfully created.

*

[root@node2 ~]# vgextend vgrz /dev/vdb2

Volume group "vgrz" successfully extended

[root@node2 ~]# lvextend -r -L 4600M /dev/vgrz/lvrz

Size of logical volume vgrz/lvrz changed from 4.10 GiB (1050 extents) to 4.49 GiB (1150 extents).

Logical volume vgrz/lvrz successfully resized.

[root@node2 ~]# resize2fs /dev/vgrz/lvrz

[root@node2 ~]# df -hT

Filesystem Type Size Used Avail Use% Mounted on

/dev/mapper/vgrz-lvrz ext4 4.4G 17M 4.2G 1% /datarz

*

[root@node1 ~]# yum install chrony

[root@node1 ~]# vim /etc/chrony.conf

pool utility.domain15.example.com iburst

[root@node1 ~]# systemctl enable chronyd

[root@node1 ~]# systemctl restart chronyd

[root@node1 ~]# systemctl status chronyd

[root@node1 ~]# tzselect

Please identify a location so that time zone rules can be set correctly.

Please select a continent, ocean, "coord", or "TZ".

1) Africa

2) Americas

3) Antarctica

4) Asia

11) TZ - I want to specify the time zone using the Posix TZ format.

#? 4

*

Please select a country whose clocks agree with yours.

1) Afghanistan 18) Israel 35) Palestine

2) Armenia 19) Japan 36) Philippines

3) Azerbaijan 20) Jordan 37) Qatar

4) Bahrain 21) Kazakhstan 38) Russia

5) Bangladesh 22) Korea (North) 39) Saudi Arabia

#? 5

The following information has been given:

Bangladesh

Therefore TZ='Asia/Dhaka' will be used.

Is the above information OK?

1) Yes

2) No

#? 1

Asia/Dhaka

[root@node1 ~]# chronyc sources -v

^? utility.domain15.example> 0 7 0 - +0ns[ +0ns] +/- 0ns

# groupadd -g 600 admin

[root@node1 ~]# find / -name natasha -type f > /home/natasha/files

[root@node1 ~]# cat /home/natasha/files

/var/spool/mail/natasha

/mnt/shares/natasha

[root@node1 ~]# mkdir /find

[root@node1 ~]# find /etc -size +5M > /find/largefiles

[root@node1 ~]# cat /find/largefiles

/etc/selinux/targeted/policy/policy.31

/etc/udev/hwdb.bin

df -hT

lvextend -L +100M /dev/vg0/vo

lvscan

xfs_growfs /home/ // home is LVM mounted directory

Note: This step is only need to do in our practice environment, you do not need to do in the real exam

resize2fs /dev/vg0/vo // Use this comand to update in the real exam df -hT

OR

e2fsck -f/dev/vg0/vo

umount /home

resize2fs /dev/vg0/vo required partition capacity such as 100M lvreduce -l 100M /dev/vg0/vo mount /dev/vg0/vo /home

df –Ht

cd /usr/local

tar -jcvf /root/backup.tar.bz2*

mkdir /test

tar -jxvf /root/backup.tar.bz2 -C /test/

• /etc/yum.repos.d/base.repo

[base]

name=base

baseurl=http://instructor.example.com/pub/rhel6/dvd

gpgcheck=0

yum list

mkdir /home/admins

chgrp -R adminuser /home/admins

chmodg+w /home/admins

chmodg+s /home/admins

groupadd adminuser

useradd natasha -G adminuser

useradd haryy -G adminuser

useradd sarah -s /sbin/nologin

Passwd user name // to modify password or echo redhat | passwd --stdin user name id natasha // to view user group.

cd /var/www/html

wget http://instructor.example.com/pub/serverX.html mv serverX.html index.html /etc/init.d/httpd restart

chkconfig httpd on