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Question 1

Tell me about yourself?

Answer 1

I have been working in customer service for many years and currently for TSA. I have a strong ethic of work. I not afraid of a new environment , I will handle problems even though Im not familiar I will look for a solution.

Question 2

Mention three tickets/incidences you recently solved.

Question 3

Can you explain any three playbooks you created?

Question 4

What is your day to day?

Question 5

If you have any conflict with one of your colleague. How would you handle it?

Question 6

Why you are the best candidate for this position?

Answer 6

Because my experience and my knowledge can contribute in your company. Also I have strong ethic of work , responsible, team player and on-time.

Question 7

If I offer you this position what would you bringing in new environment?

Question 8

What is your patching process?

Question 9

After patching System doesn’t come up. List some of the steps you’d take to revive it?

Question 10

How can you go into Single User and its purpose?

Answer 10

Init 1 or during boot stop the process and press “e” then add systemd.unit=emergency.target
Emergency mode basically for maintenance.

Question 11

Describe Linux Boot Process

Answer 11

BIOS - Power on Self-Test. Performs some system integrity checks. Searches, loads, and executes the boot loader program.
MBR - Master Boot Record. It is located in the 1st sector of the bootable disk. MBR is 512 bytes in size. It contains information about GRUB. So, in simple terms MBR loads and executes the GRUB boot loader.
GRUB - Grand Unified Bootloader. Loads the default kernel image as specified in the grub configuration file. Grub configuration file is /boot/grub/grub.conf. It contains kernel and initrd image. So, in simple terms GRUB just loads and executes Kernel and initrd images
Kernel - Mounts the root file system as specified in the “root=” in grub.conf. Kernel executes the /sbin/init program. Initrd is used by kernel as temporary root file system until kernel is booted and the real root file system is mounted.
Init - Looks at /etc/inittab to decide default run level.
Run Level - Executes run level programs from the default run level

Question 12

What are different run levels in Linux?

Answer 12

0= shutdown/emergency mode
1= single user
2= multi user w/no network
3= multi user w/network no /GUI
4= not used or undefiened
5= multi user w/network and w/GUI
6=reboot

Question 13

How can you perform a Filesystem Consistency check on a partition/hard drive?

Answer 13

Run the fsck utility on the partition, specifying the filesystem type and the device name.

Question 14

How do you force unmount a hung nfs share?

Answer 14

you can use the umount command with the -f or –force flag.
umount -f /path/to/nfs/share

Question 15

How to go into Rescue mode.

Answer 15

reboot the server
b. stop the grub menu by hitting any key
c. select the kernel
d. press e to edit kernel cmdline entry
e. go to the end of line starting with Linux16 and type init=/bin/bash
f. hit ctrl+x
g. mount |grep root
h. mount -o remount,rw /
i. passwd
j. touch /.autorelabel
k. /sbin/reboot -f

Question 16

A service (sshd) fails to start. What are some of the troubleshooting steps you’d take to fix it?

Answer 16

Check the service’s log files for any error messages or other information that might indicate the cause of the problem. The log files for the sshd service are typically located in the /var/log directory.
Check the service’s configuration files for any errors or misconfigurations. The configuration files for the sshd service are typically located in the /etc/ssh directory.
Restart the service to see if the problem is resolved. You can use the systemctl command to restart the sshd service:
Check the system’s firewall rules to ensure that the service is allowed to accept incoming connections. You can use the iptables or firewalld commands to view and modify the firewall rules.
Check the system’s network configuration to ensure that the service is bound to the correct network interface and port. You can use the netstat command to view the network connections on the system.
If the problem persists, you can try stopping and disabling the service, and then re-enabling and starting it again to see if that resolves the problem. You can use the following

Question 17

How to check a Service is enabled/disabled and at boot time/persistent?

Answer 17

systemctl status service name

Question 18

How can you change the root passwd in RHEL 7 if you forget it?

Answer 18

Reboot the system and press the “e” key on the grub menu to edit the kernel command line.
Find the line that starts with “linux16” and add “rw init=/bin/sh” to the end of it. Press “Ctrl + x” to boot the system with this modified command line.
Once the system has booted, you will be presented with a shell prompt. Type “mount -o remount,rw /” to remount the root filesystem as read-write.
Type “passwd” to change the root password.
Type “reboot” to reboot the system normally