Preping for the LFCS!

Here’s my latest venture into cracking one of the most demanding certification as a DevOps Engineer.

One fine day, I got highly interested while working on handling Linux issues. As I kept going at it tirelessly, my curiosity & passion for this piece of technology grew bigger and bigger. Consequently I had made my decision to pursue the Linux Foundation Certified System Administrator Exam.

I searched through various blogs and writeups on how to prepare for this exam. Here are some details that one should know while preparing for this exam:

1. The LFCS exam is a 2 hour practical hands on exam which tests your skill on the Linux Operating System Ubuntu 20.24.
2. Since the UI of the exam has changed a bit, I recommend a thorough practice session on https://killer.sh/ simulator in order to get familiar and as well as to avoid any surprises. This would greatly enhance your abilities to attempt questions within the alloted time.
3. Do not make the mistake of getting stuck at a particular question for a long time you can always flag it and get back to it later. We can make a small calculation on the estimated time per question.
4. We have a total of 2 hours, 16 questions which means 2*60 = 120 is our total time in minutes. If we take about 7 mins per question we need about 16*7 = 112 mins to complete all of the questions. Now, not all questions require 7 mins some can be answered under a minute or 2. So improve your time by practicing a lot.

I had about 4 questions where I had struggled initially to solve them, I flagged them but I was able to clear other questions satisfactorily. Some of the questions that I can remember were the following:

1. ssh to the given machine and find out the process on the mounted volumes where there is high consumption of resources. I knew to check for the mounted volumes so I did

ssh web-app
df -hT

but I couldn’t see the PID nor the process where consumptions of resources were high. So then I checked the following from the ps list:

ps -ef | grep "/mnt/volume-name"

this immediately gave me the PID, Process name & as well the IO rate i.e. Input/Output consumption rate which were higher than other mounted volumes.

2. Create a volume group for a physical volume & Create a lv named lv-data and extend it by 0.2 G. Format this volume using ext4 filesystem.

I had forgotten the format to write the lvextend, I had flagged it and came back to this question and searched it via this command

sudo lvextend --help

sudo pv create /dev/vdb volume1
sudo lv create --name lv-data -size +2.0G 
sudo mkfs.ext4 /dev/volume1/vdb
sudo lvextend --name lmv -size +0.2G /dev/volume1/vdb

Most Importantily the help & man pages gives ample list of commands which helped me to get through the exam.

Some of the materials that I relied on for passing the exam were:

1. Kodekloud LFCS resources: https://kodekloud.com/courses/linux-foundation-certified-system-administrator-lfcs/
2. CloudGuru LFCS resources: https://www.pluralsight.com/cloud-guru/courses/linux-foundation-certified-system-administrator-lfcs
3. Killer.sh: https://killer.sh

So finally I received my certification in my first attempt itself: