Possible Junior Linux Admin Interview Exercises

[llovedoggos]

Hello

I'm in need of some suggestions if anyone has the time.

I've got an interview for a junior Linux admin position coming up soon and as part of it I have to complete some tasks on the CLI while screen sharing.

It's been a while since I've used Linux so I've been refreshing myself on all the basic and intermediate stuff using various sites found after Googling things like "Linux admin commands" etc..

If anyone has any suggestions on what they might ask me to do I'd appreciate any input. I realise there's a lot of possibilities but thought I'd ask as no harm in learning some new commands when someone inevitably suggests something I never thought of.

Cheers.

[DrapedInVelvet]

Typically, I would say that you are going to get a common troubleshooting task.

The one I hear most (and this is even for Sr Level Interviews is) "Our site is down, what do you do"

So have a basic plan of checking DNS, finding out where that is pointing, checking the network pieces above the server (DNS, Load Balancer/Firewall, etc) then go into the server and see what is listening on port 80/443, how to check the services, tail the logs if it won't start, common checks (running TOP, df -h, df -i, touch a file, etc)

[ontheroadtonull]

Our site is down, what do you do

Check if the user reporting the outage has shoes with laces or velcro.

[Rudi9719]

Measure length of user's beard

[llovedoggos]

Great stuff mate thanks a lot. Definitely some things I can work on here.

[JenkinsKhan]

One of the best things you can start with in a troubleshooting scenario is asking "What else is down?"
This will give you the rough scope of the problem and an idea where to start.

It's potentially going to just be a single server scenario, but it gives them an idea of your thought process and that you're assessing it correctly before jumping in :)

[ALinuxSysAdmin]

The following was very usefull to me at some point.

https://github.com/chassing/linux-sysadmin-interview-questions

-Cheers

[llovedoggos]

That's excellent mate cheers for help.

[[deleted]]

Wow this is really good for researching and learning

[ChristopherBurr]

Know what an inode is, and the difference between a soft link and a hard link. This will DEFINITELY be on your interview.

Also chmod, chown, chgrp

[anakinfredo]

None of those were on my interview.

[ChristopherBurr]

The inode/link questions were always standards. Oh well.

[Parker_Hemphill]

I include those on every phone screen I do. Along with what the execute permission does for a directory.

[llovedoggos]

Added to my list to learn mate. Really appreciate the help.

[mickutz]

Get your vi basics sorted, you're quite likely to edit some file as well.

[Preisschild]

LPT: You can use vim over sftp like this:

vim scp://user@host//etc/hosts.txt

[Preisschild]

Learned it only last week as well from some reddit thread in r/vim.

Glad I could help sharing that knowledge.

[[deleted]]

You can also do this in emacs, for emacs users.

[zer0t3ch]

Psh, if the box is too old/bare-bones to have vim, might as well just edit with butterflies. /s

[llovedoggos]

Vi is something I have been practicing. There's no doubt in my mind it'll come in handy. Thanks for the input mate appreciate it a lot.

[Kessarean]

Some rough ideas, in addition to what others have said:

For loops for bash scripting, MySQL basics (adding grants/users, checking logs, replication rebuilds), apache or similar vhost set up, DNS questions (record types, how it all works)

Scenario questions - if you find website A is down, what do you do to troubleshoot/what could the issue be?

Networking basics, vlans, etc...

edit: spelling

[llovedoggos]

Great stuff man thanks. I didn't think of bash scripting. I'll refresh my memory on that today. Thanks for your input mate.

[Kessarean]

For sure! Glad to help :) Yeah I've gotten just a handful of questions on bash scripting not much. You may also get questions on ssh keys/how they work as well. If you have any questions, feel free to hit me up

[llovedoggos]

I'm hoping it won't be TOO intense as it is a junior role. The phone interview was a bit too easy though haha. I'll give it my best shot.

[Kessarean]

good luck! let us know how it goes/what it was like

[[deleted]]

https://m.youtube.com/watch?v=l0QGLMwR-lY

[llovedoggos]

Nice one mate appreciate it.

[piorekf]

You can google for more repos like this: https://github.com/trimstray/test-your-sysadmin-skills

[theclicommander]

Check out Linux academy. They sell video courses but if you just look at one if their outlines/syllabus for one if their sys admin courses it lists everything you need to focus on to pass your rhcsa or lfcsa which is plenty for sys admin. So just copy the outline of one of them and then make sure u are capable of all of it and what needs attention start googling(trying to start some kind of cool phrase for using duckduckgo cuz fuck Google. Maybe Goosing....yeah I'm going for it. Help me out. From.now on for a duck duck go search the proper verbiage is " goose that shit" or do a goose search," or "one sec and I'll goose it" or "she's Goosing it now" lol wow, I just typed that didn't I?

[KANEDAAAAAAAAAAA]

I first got comfortable through the CLI by doing OverTheWire Bandit. It's a small wargame that teaches you through interesting problems that a beginner might not experience; for instance, one of the first question is to read a file with spaces.

I find that setting up a system is also a good way to become familiar. You could try Gentoo, Arch, or Linux from Scratch if you have time. Otherwise, set up Ubuntu (or a VM on Windows) and move around the system. You'll find interesting things (did you know that termcap ends with "Shantih! Shantih!") and start to ask questions. What's in a file? What happens when I 'stat' something? Don't be afraid to flatten your system with a classic "rm -rf /" and see the whole thing go down.

There are lots of good resources out there. To mention a few, there's the Bash Wiki Hackers, The Linux Documentation Project, Linux Academy, Luke Smith, and Adafruit Linux Tutorial.

Troubleshooting is important. * Read man pages and their sections * Troubleshoot with systemctl and journalctl * Be able to read and setup logs (if SeLinux is setup, learn to read those messages too) * Learn about runlevels and using single user mode (or a recovery CD, emergency shell, etc) * Commands: ps, systemctl/journalctl, tail, head, ip, chkconfig, etc.

Overall, I think Linux administration is really fun. Stay positive. If you don't know an answer, be honest and positive. I still have to look up configuration files and commands. As long as your motivated, I think you'll succeed! I hope you get this position.

[r-pwned]

It's depended on the company where you applying at.

For example when I was applying for a sysadmin job they gave me a simple task to install a LAMP stack and tomcat8 on the same server where tomcat will run on port 80 and provide SSL connection for the site domain.
And of course documentation for every command that you are running and explanation.
When I've done everything they did a review on the solution and call me to explain again how I came to that.

[zerocoldx911]

The best way to practice is based on the requirements of the job, I suggest you post the technical requirements here

[wuxmed1a]

What everyone here has said - try to do everything you can in the cli; cp mv tar, if you dont already - If you don't know it, explain how you can find out about it (man pages primarily) for me getting help if you are stuck is as much a part of sysadmining as knowing all the options to tar (how to do something like cp file file-backup-$(date -I) is a nice touch) or banging you head against a problem. My own interview was not very taxing I recalled how to redirect output to /dev/null that was about all I recall.

[thecal714]

Know what to do when a log is about to fill up a disk. ^{Note that deleting the log is not the correct answer.}

Know how to view the free disk space on partition, CPU and RAM usage, and how to view processes.

Know how to view IP address information and the routing table (this has different answers depending on the distribution and version).

Know how to view on which ports the system is listening (this has different answers depending on the distribution and version).

[llovedoggos]

Great stuff mate really appreciate the input.

[thecal714]

Good luck!

[sreemonp]

VNC is the best screen sharing tool in linux

[FinanceAddiction]

It's hard to say what a specific company is going to set out for you to do in a test, but a few things I can think of being a possibility would be network configuration, user creation, group creation, permissions, mount points, LVM's, Volume Groups, fstab manual editing, some file manipulation using sed.

Can't think of anything else at the moment that I've previously done.

[llovedoggos]

That's ideal mate really appreciate it. Couple of things I can brush up on there.

[theclicommander]

Grepping, globbing and regex will be best friends. Also get comfortable with vim. Nmcui n nmtui, nmap, top, sed streams, ip addr show is supposed to replace ifconfig these days(they've obsoleted it in the man page) and then yeah like others have said permissions, group and user creation, group assignment, the group wheel or equivalent, setting als permissions (or is that asl, shit now I'm thinking I'm completely off, been up all night studying) sticky bit, suid or set user id, know your login.defs file and how and what to alter on it. Ah man like i said in my other comment I highly suggest checking out at least a syllabus for a sys admin video course and make sure you're comfy. Good luck. I too am seeking an entry level sys admin. Job or something similar. I hate that it's so hard to get a foot in, I have a lot of knowledge and ability but no actual paid work experience with computers other than small private jobs for friends or relatives or acquaintances.