I find it funny that with 28 years of linux experience, 25 as a professional linux admin/engineer I still get asked some of those questions. Though the funnest one I have had was an interview a few years ago. I was asked how I would stop an HA pair that when booted was caught in a boot loop. System A boots and forces system B to reboot, then system B forces system A to reboot, etc. I asked which version of Linux they were running and the Tech responded with RHEL 5.5 I let them know that there is a bug in 5.5's init setup. On a default install the ntpd service starts after the HA services. That time jump causes it to fence the other host and reboot it. You can fix it by changing the ntpd service to start before the HA services. Next thing I know, I hear lots of typing and the tech says "Holy cow, he's right" The manager then tells him to get the change notices in so they can fix the issue once and for all. I asked when I could start and was told they had other to interview and would be in touch. 6 years, Im still waiting to hear from them. lol They never contacted me and never responded to emails after the phone interview. It just reinforces the old adage, if you know what is wrong dont give them the solution!
Daniel Livingston Probably the Guy on which he was speaking to, just gave himself the originality of credit .. (he said that it was his idea).Said to hear that OP got fooled
Integrity isn't dead, but some organizations work hard to kill it. Consider it a gift from God that you didn't get the job in that snake den. Thank you for sharing the tech tidbit and retrospect.
Dropping a comment to let anyone who is watching this in 2022 that this is very good information. Just had a tech screen today which asked 6/9 of these questions.
I've been a linux admin for 20+ years (originally as my actual job, for the last ten years purely for my personal stuff) and saw this video and watched it on a lark. I honestly expected some cringeworthy content - but was pleasantly surprised to find that it was all good basic info, presented fairly well (obviously VERY basic, but given its target audience that's fair). I would add only one thing, to the "listening network sockets" question: lsof -i can often be more useful and easier to use than netstat.
I know a system admin that always type in "netstat -plant" or "netstat -plantu". I have muscle memory to always use "netstat -natpl". And I always use "ls -alF" via muscle memory.
I'm an advanced linux user and administrator. Using linux both with my work and full time on my private computers (I've ditched Windows and Mac OS X completely). I already knew the answer on all those questions. It is a well done video, bringing up the basic questions one would actually asked in a linux job interview. One thing to be prepared for, in such an interview, is to be ready to answer "I don't know ...". Some ask tricky questions that is hard to answer without knowing the companies computer/servers in detail at first. Questions only a person hired at the company would know. They ask these kind of questions to see if one is capable of a "I don't know. Let me find out.", or if one is more like a person who tries to blab on about things one don't know anything about.
Your interviewer will not like an I don't know answer as to them that sounds like your just giving up. They want to know what you would do to try to trouble shoot the issue. For example start asking them if the servers are on the same local network or across a router and verify if the routing tables are jacked up etc. They want to know what your ability to troubleshoot and solve problems not drill you for rote knowledge,
@@carlosgarza31 That depends. I think that it is a completely false notion that people expect you to know everything (because the reality is you can't know everything, although that shouldn't stop you from trying), and if someone EXPECTS you to know everything (again, depending on what it is), then I'm not so sure that I would want to work for that person or that company. Either they should be creating an environment from which you can grow and learn (and invest in you as a human resource) or they're expecting to treat you like a trained monkey and ONLY do what they tell you to do and nothing more/nothing less. Yes, there are basic aspects, and even some intermediate aspects to a person apply for a job, but I usually will ask someone a tough, challenging question, preferably something that they haven't seen or dealt with before, because I'm looking to assess their problem solving skills, not how well they can memorize stuff and ONLY execute the stuff they've memorized. If all you're doing is like basically the human version of a digital janitor where all you're doing is just cleaning up someone else's stuff, then fine. But if I want you to actively be able to solve problems - both foreseeable and those that were unforeseen, then your memorized scripts and procedures may not work and I need people who can solve problems AS well as being a "digital janitor". (Heck, a "smart" digital janitor would automate the job for themselves so that they can do other things that they want to do.)
@@ewenchan1239 I think its more fair to say usually the interviewer for what ever reason assume they know more then the applicant. I see it in my coworkers all the time when they grill applicants.
Commands to Know: uname -a / ifconfig or ip addr show / df -ah / service status or systemctl status / du -sh code/ / sudo netstat -tulpn / ps aux | grep or top or htop / mount /dev/sda2 /mnt or mount / man / / Google & others
In an interview you should begin the answers with something like "I would do it with ...." because there are multiple ways do do stuff on Linux and it will show the interview partner that you're aware of that ;)
From one sysadmin to another: Kudos on showing the modern equivalent to these commands! I feel like a lot of tutorials cover only the old way of doing things, which is quickly going out of style on recent linux distributions. There is one I would like to add: "ss" seems to be replacing "netstat" nowadays, though the syntax is very similar ("ss -tulpn" works as you would expect).
Sometimes useful for when you don't know what commands are associated with what you're trying to do is "man -k whatever". What you're looking for may not be there, and if it is then there will probably be also all sorts of other stuff that isn't what you're looking for, but sometimes it pays off. I tend to use it before resorting to google, simply it's easier to wade through the results. If your - key is broken, "apropos" is a synonym for "man -k". Which, of course, you knew because the first thing you do with man is "man man" :)
Thank you. My name is Frank Ayerdi and I am in Linkedin. I am teaching my 9 year old Linux and he now has his own computer. I found your video very helpful.
I don't care about the questions, but the little idea of putting my name into config files I chanced to be sure to find every single on when migrating might just have changed my life!
nmap and netstat should really both be accepted answers. But as an interviewee I would mention netstat also and see if the applicant is familiar with it.
Ive come from business area, entire life work focusing on finance and then, BANG, my boss sends me to IT area. I have to confess I used to read hardware books while on graduation just for fun and that I always wanted to know more about Linux since I was a kid and had read about hackers and stuff. But damn, boss had gave me an opportunity to focus on another area and I had to run to learn more about it. Got my Comptia and LPI certifications on Linux, studying for RHCSA and doing a course on oracle. Gota get some more certifications or my short time working as sysadmin may be frustrating in the near future =] Working in IT since 2015 and in love for Linux =D
As a 15 y/o, I have used Debian based systems for almost 2 years and I can answer all of them. They don't seem that hard, but is this really it about being a sysadmin? There must be more to this than that.
Well from using Linux since the 90's as a personal thing. I guess if that's all they wanted to know then I could easily be a sys admin for a living instead of just as a hobby.
@@yatoxic1213 these questions tell if you have very basic Linux knowledge. It's like asking a car engineer "how fast is the car going" "how much fuel is left" "what gear is the car in". I can imagine one or two of these questions being asked in the beginning of the interview in order to make sure nobody is wasting time. After failing to answer, the interview is over and if you got them good, the interview will start and you'll get proper questions based on the actual job you are applying for.
I had my first ever interview today for a junior linux sysadmin, about 4 of the questions from here where asked. a few more include; how to compress a log file, config file for kernel, how to ssh into a server when the server is down. i was so nervous, i did not make it to the next level. I have another interview coming up in a couple of days, still nervous, but working harder.
Congrats on interviewing! Don't worry about the interview stress -- it will get more and more manageable with each interview you do. Just focus on why you love this stuff and ask interesting questions about the company/work environment. Wishing you luck.
I watched this video before some months, I didn't knew most of the staff, after 6 months of reading and experimenting with vms I know almost all the answers, great video!
I was once asked to write, on a blackboard, a firewall rule using iptables, as part of the job interview. Was a very pleasant interview, because I totally didn't expect these kind of questions and it shows what kind of employer you're going to get. It did however inspire me years later to create a 'broken' Linux system and have new colleagues try to fix as many problems as they could, in a specific amount of time. It tells a lot about the person. Not many people can fix "the chmod binary is set to non-executable" problem without resorting to Google for the answer.
I've looked it up, thanks for sharing such things, the easiest way I found was to copy another executable file to the original file as this will inherit the +x flags.
I remember watching this probably a year or two ago and writing everything down and thinking to myself that I’ll memorize everything and be golden. But what you said in the beginning is right you gotta use it before you even know why it’s there in the first place. Well now a year or so later and I can answer all of these questions truthfully and give you exact reasons as to why I know the answer to each of them. Thanks for the video it taught me a lot and prepared me for what is to come!
For dealing with mounts, my favorite command by far is "lsblk" because it shows all your mounted and unmounted devices in a very neat and readable manner. Kind of like a well formatted version of the command "mount" (only if you're using it to display info).
I wouln't take that 5% for granted as when your disks user space fills up your system will be so damaged the only one that will be able to login at that point is root in single user mode most likely at that point. Certainly user level processes won't be able to do anything with it.
so? you make an alias like this: alias df='alias --sync -ha' then EXPORT it or save it in your .bash_aliases file .... then logout / reload your shell. Bingo or voila. it now SYNCS all the HD caches before showing you the latest stats.
I had to use Linux in some of my courses and I learned more conceptually from this video than any of my professors. I understood everything you covered and then some, but the way you explained it filled in little gaps in my knowledge. I never knew "htop" was a thing. Just top haha. You got yourself a sub.
Tutorial Linux, I just want to thank you from the bottom of my heart as a 2nd year transferring to another school as a first. I could hardly grasp shells and grep, most specifically assigning access for different users/groups. I really appreciate the head start that you give guys like us who want to find a passion for networking. And I'm not going to lie the language barrier was really killing me, I can work with what I got but your voice sounds like angelic hz
Here's a few I ask: 1 - How do you add a new disk to a linux VM (typically) without rebooting? 2 - How would you go about recovering a root password that you don't know? 3 - Why would a file system APPEAR full even though a "du -shc" shows that there's not that much space taken up? 4 - How do you add space to an existing file system in LVM? and to see if the candidate has any network debugging experience: 5 - You've got a DNS server that's one router hop away on the network but you can't do a zone transfer. What are some things you'd check?
@TutoriaLinux heyas thank you for this video! I can't believe these are questions to a job interview because they're so easy and it's basic stuff. Coming from an ex windows power user I am completely in love with Ubuntu linux and I will always remember these important commands. Thank you!
...and I felt so good about myself (about a decade of exclusively using Linux at home, no professional experience at all) getting a 9/10 on the original list of questions (forgot about netstat as that too I never need at home)...your list I would fail horribly as none of that I have ever come into contact with at home. At least you gave me something to man/google...
of those, i need to learn: 1,2,4,5 but answer to 3 is just simply this (in non tech or CLI terms): SLACK space and the structure of the formatting used on the filesystem in question :) and was there compression or no?
@@tutoriaLinux hey man is there any place I can donate to your page or something? I just bought the course on Udemy and look forward to learning even more.
Professional Enterprise Linux instructor here. I watch videos like this mostly for laughs because they usually feature someone who is trying desperately to make up for lack of true understanding with confidence. I kept waiting for you to say something stupid or completely wrong, but it never happened. You answered every question almost exactly like I would have. If it's worth anything to you, you've definitely got my seal of approval!
Thanks a lot Dave for these super videos. I went through all of them in the "The Linux Basics Course: Beginner to Sysadmin, Step by Step" playlist and you rock !! I Learned a lot more to move in the Linux world as a Sysadmin. Thanks again !!
For me it is so much more important that some one understands what is actually going on with the system architecture and how it all fits together rather than memorising commands and syntax. Most things asked here can be done in a variety of ways.
2:50 - checking IP address: ifconfig is deprecated since 10 years already. You should use 'ip addr show' or 'ip a s' for short or even 'ip a' shortest version. Latest linux distros doesn't even ship with old net-tools which contains 'ifconfig', but they ship with iproute2 which contains 'ip' command. Also: old 'ifconfig' doesn't show multiple IP Addresses on single interface which 'ip' does. And this is different than interface aliases. Same with 'netstat' vs. 'ss'.
You can also use hostname -I (capital i) to list all the IP addresses for a host (omitting loopback and link-local addresses) - easier than trying to pick through the output of ip a. As others have pointed out, ifconfig and netstat are deprecated, and have been for a long, long time. RHEL7 / CentOS 7 has already dropped it from the base install, and the Debian people are working on it.
I never, ever ask technical questions when I interview. People are super nervous and can always forget names, etc. Better to actually watch them do it on a machine.
'How to ask questions the smart way' is gold. Been a while since I have seen it mentioned. Shame it hasn't been updated in nearly a decade. Having said that, a lot of it is timeless wisdom needs to be read.
Now i'm thankful to my 5th grade teacher he told these and also gave us lessons for typewriting. These are essential skills even if you are not into IT.
@@pavloskairis9994 It probably wouldn't work in a job interview, but I would've called someone who did. I'm really good at searching for solutions to problems, so I'd ask them to search using my search term. I'm well versed enough in Linux to only be told what the commands and stuff should be, so they'd only have to read what they find.
No. _Knowing_ what to do is the most effective, nothing is faster than that. No one wants you sitting around googling things you are supposed to know by heart while your client is dead in the water and losing money with every minute of downtime. P.S. Of course you can't know everything, but if something comes up often, you should know it.
Novice Linux user playing with Linux. Though these are interview focused, they helped me get a quick transition view and calls to investigate further. Thanks for sharing!
Thank you for this - this confirms that I am studying the correct information. I would have been able to answer all those questions intelligently, adding "info" to #9. Example how would you look up information on something you you don't know? I'd answer "man or info - into gives the same information presented in a different layout".
Agreed. Usually info contains MUCH more info about like how the program actually works rather than just how to use it which is what man is better for. For example the man page for "make" will just simply show you how to use the make command, but the info for "make" is extremely detailed and helps you with writing makefiles and shows you how they work.
9:57 "pgrep" or "ps -fp $(pgrep ...)" can be more useful instead of "ps | grep" in case a server runs a lot of processes and it's very slow due to overload
It's good to know both. net-tools will be around for a long time on Debian, CentOS, and RedHat servers that new sysadmins will maintain. You're absolutely right, though -- I should make a few videos covering the new iptools suite.
I work in a big governemental agency in France and we've got more than 1500 linux servers in production. Versions are redhat 5, 6 and 7. Your advice does not apply for RHEL5. RHEL 7 is systemd while 5 and 6 are classical SysV. One must know both versions.
Here's my answers: 1: ls -l /vmlinuz (Yeah, i know, pretty dumb method, but it works) 2: in Bash or in X windows? 3: df -h 4: I'll have to google the command first 5: du -h 6: Google for the command, again 7: ps aux | grep 8: sudo mount /dev/sdx1 /mnt 9: If I don't know the command, google for it. If I look for a command, which command. If i don't know how to use a command, command --help, or man command 10: Just google it. Most likely someone has already asked the question before, and got an answer
Pretty fun as a quiz, got them all except netstat, I would use nmap, and I would have to look up its arguments - I don't use the functionality often at all. With the "how would you mount a usb drive you had just plugged in" I would add "dmesg | tail" to get the device name first.
1:50 How to the check the kernel version of a Linux system 2:50 How to check the current IP address on Linux 4:03 How to check for free disk space in Linux 4:55 How to see if a Linux service is running 6:33 How to check the size of a directory in Linux 7:02 How to check for open ports in Linux? 9:48 How to check Linux process information 11:49 How to deal with mounts in Linux 13:51 Man pages 15:04 Other resources
I'm a hardcore IT Engineer with Linux experience and you're brief tutorial on Linux was helpful and informative. I don't pretend to know all their is to Linux and I don't know many IT Engineers that do since Windows has made most of us lazy, although I've rediscovered Linux for my interest in web development and I've gone too long without a dedicated Linux Server in my home office. Subscribed and Liked plus I intend on checking out all of your videos since Linux has come a long way since last I played around with it.
Good video for beginners. I'm not a systems admin but I've interviewed for such positions and almost never get asked these questions. I usually get asked things like, "How do you find a failed disk in a raid configuration" or "How do you spin up a new virtual for load capacity" and weird stuff like that.
Agreed, I am in no way a linux sysadmin, but I can do some stuff. I use google to help with errors. These questions seemed so basic. I had a Magento site which a hosting company's admin could not fix a problem with a php error. I later found it was related to the permissions of the files, but once I upgraded to a more recent php verison it was rectified. I was surprised their admin was unable to easily fix it.
i never pursued a certification apart from my associate degree in IT. but i’ve used tons of linux distros and the last 4 years i’ve been using only fedora. and i kinda knew like 8 out of 10 here. still this is really informative and good to know as reference material. specially if not used on the daily.
Appreciate it! I can't even count the number of angry comments I get about these questions, but the reality is that they STILL show up in a huge percentage of interviews. I suspect they'll be around for a looooong time.
Other questions are: how to reboot a system without everybody shouting at you, how to know who else is connected, how to make a backup and how to restore, how to synchronize systems. I loved the advice not to fake knowledge! I was often very much pissed, because every interview is taking time and preparation. I do not require top gun system operators, but if you hire one, you want to be sure they know how to move on without destroying a server or system.
@tutorialLinux : I might be mistaken but I think you might be confusing the role of 0.0.0.0 in the local and foreign address columns. as far as I've understood it, in the local address column it means "any of my own IP addresses" in a scenario where you have multiple. Let's say for example you are in 2 LAN's and you'd have 10.0.3.1 and 192.168.3.1 assigned to the same machine: clients can connect to either, and they will see an open port 80. If they want DNS (port 53), they will get that service when connecting to the 10.xxx address but not when connecting to the 192.xxx address. In the foreign address column, it means "Any external IP address" which signifies the IP (or subnet) of the client connecting to you. Please correct me if I'm wrong, but that is how it was taught to me.
Yep, that was a pretty dumb miscommunication on my part. It's "all of my IP interfaces," not just "all public IPs." The reason it came out of my big dumb mouth like that is because just before filming this video I'd been doing a bunch of nginx config stuff on some servers with multiple public IPs (trying to get the right website configs to match the right ip/server_name combinations) and only had public IPs in my head. Thanks for pointing it out!
All this works also on macOS. Nearly everyone can learn that on-the-job if needed. I would ask other questions. For example how you find answers if you don't know something. Etc.
How are you supposed to become a junior linux sys admin if you are exactly that - a junior in your career with most likely no profession experience? Where is the step from no professional experience to professional experience, if every company wants you to have X many years experience, even for a junior role.
I think job ads generally tend towards being stupid and misleading. Most have been either created or severely edited by an HR person who has no idea what the job is actually about. Every IT job I've ever had required a College Degree (which I don't have), according to the job description. Every one of those companies has been open to self-motivated juniors, which is how I got started. As soon as you talk to an actual technical person, it's about demonstrating that you've got the skills you need to be useful right away, that you've got the motivation to learn and improve in your spare time, and that you've got the proper personality and instincts to keep from screwing up too badly (caution, double-check mentality, good writing skills, social skills, patience, lack of arrogance, etc.). Nothing in a job ad is carved in stone. Apply anyway and make sure you have a good story about yourself and your background, and sooner or later you'll get a chance.
Very true regarding flexibility of job apps. However, as you say when you have HR people editing and often recruiting for these jobs (who may not be very informed about the role) you often have those same HR people initially sifting the applications as a first round. The issue I found is that I wasnt even able to get to a stage to prove myself by answering questions like this because, on paper, I didnt appear to match requirements. To explain, I do a lot of sys admin related stuff in my spare time. None of it is paid, its all for fun/to help community's I am part of. However, because it lacked the word *Professional* this experience didnt hold any value to the initial interview sifters who rejected me. After asking all of them why, the ones who replied said it was due to "lack of relevant professional experience". I also find that it is very difficult to prove that you are motivated and willing to learn if you have no relevant experience on a resume , especially if your resume is the only factor in your initial application process (which it is 99% of the time).
Yeah, what you're saying is absolutely true in my experience as well. The way I found around this was to target small companies (~20 people) that weren't big enough to have HR drones, and then apply for internships and junior roles at those, using super customized cover letters. After applying, it might be worth it to contact the hiring manager (company tech guy, at a place this small) directly and give him a 10-second version of this story (applied, worried I'll get sifted by HR before I can prove myself in an interview, love your company and wanted to ensure I get a fair shot). Also, it might be useful to rebrand your community volunteering as "Open-Source" work, if there's any way that might apply. If not, consider writing some scripts or programs to help automate your volunteer work there, and put them up on Github. HR drones learn slowly, but "open source" is a word they are starting to recognize.
+CardinalHijack As Dave hinted, you must become "creative". He suggested shoehorning "Open Source" in there. My relative called years of unemployment "working in import/export overseas". So whether you outright lie or just "re-interpret" your experience (because you do have experience -- its just not professional (read: paid) experience) your goal will be to get past the gatekeeper and force them to see how good you really are for the job. And sometimes that means... "exaggerating". Good luck!
I like the fact that I got most of them right and only got into linux last month or so. I'm not a total noob, but it's nice to see that I'm trying to learn more "advanced" stuff from the start :) but then again yesterday I was at a lost and literally caught myself googling (out of frustration) "how to pin linx!".... 2-3 minutes later I realized I forgot to plug in the cables :) My soft setup was fine, just that I forgot that I was testing redundancy and "accidentally" unplugged both ports.
Haha yes! These are definitely basic phone screen questions (not enough to actually qualify someone to *do* the linux/infra/devops job), but they're still REALLY popular filters. 90% of applicants can't answer them.
Thanks for this, it's very useful! :) Luckily I knew all the answers (with a short hesitation at netstat). Though I'm more into programming than system administration, I use Linux because it's beautiful! I'm about to finish a huge book on C++ this or next month and then I'll see what the market has to offer and what's next maybe Python or D.
I use a lot of Python (excellent for job prospects), but D is a *really* interesting language. I'm far from a pro with D, but it's definitely an interesting one to learn. Again, if you're about to engage in a job hunt, Python will probably be a better time investment in the short-term, though :-).
Great video! I am 19 years old and started working with Linux about 3 years ago, was happy know the commands you used and understand the explanations you gave.
Thanks for this. I've been a mostly Windows Admin. My linux experience has been limited to playing around at home. Although, I have used all of these commands in the past, a few did not come to me fast enough to impress at an interview. Most were "dammit, I knew that". Guess it's time for refreshers.
Great video tutoriaLinux. I was surprised by number 10 however. Many developers(most?) include both a man page AND an info page. Usually if there is only a man page, the info system will just display that. The info page can go into incredible detail about how to use a program - including tutorials. Also, showing these two commands would have been very helpful to people just getting started: "man man", and "info info".
Yeah, I need to do a new (and better) video on where to find help/resources/docs. There are so many great resources I haven't yet mentioned in any videos. Just gotta find the time...
Well I learned something new, so I'm not complaining. For 22 years I've been using "du -h" or "du -hc", and being annoyed by the output... If I'd only read down to the -s section... So, thank you - I subscribed - looking forward to watching your old and new vids!
OK, without watching the video I'll see what I can recall from memory to answer the timestamps 1. uname -a 2. ifconfig 3. df -h 4. htop? netstat? sudo service something status 5. df something 6. netstat something localhost 7. htop 8. /etc/fstab? 9. man something
I feel like these aren't even jr. sysadmin, these are just linux user level... Though it definitely weeds out those who are utterly useless for the position (remember, this is just phone screening).
Yep, that's exactly it. These are some of the most popular *simple, basic* interview questions I've seen/used, precisely because they can save a huge amount of time by weeding out candidates that aren't competent with a wide variety of the basics. As you pointed out, KNOWING THESE DOES NOT MEAN YOU'RE READY FOR A SYSADMIN GIG, BUT *NOT* KNOWING THEM DISQUALIFIES YOU IMMEDIATELY. There are scores of people who respond to job ads who can talk a good game about scaling, best practices, pros and cons of different products, behavioral questions, and more. A huge percentage of those people then proceed to blow every single one of the basic questions in this video. These questions are a great way to avoid the sysadmin version of "architecture astronauts" (a popular term in software engineering), who can tell you about design patterns and computer science concepts all day long and then fall down when they have to write fizzbuzz (google it) or similar ultra-simple programs.
Well, you haven't *disqualified* yourself, which is exactly the point of these questions :-D. Answering these (along with about ~20-30 minutes of more open-ended troubleshooting/experience-testing questions that aren't in this video) would at least keep your resume from being thrown out.
:D 10 out of 10. Totes patting myself on the back, lol. Great video. Also want to point out that for number 10 you can use help flags such as: "--help or -h" for most commands. :)
@@p5eudo883 Accidentally fcked up my manjaro and now I am fiddling with a timeshift backup that just doesnt want to work xD its a strange ride but I´ll get there ^^
@@flyfight98 I first started learning about Linux back in the 90's in HS. Messed up, learn how to fix, and learn why not to do that again. All part of the learning process :).
Adi Serghei Most employers want to make sure you got some experience, so it's not mandatory to have super hard questions, but the difficulty will vary, based on the position you are applying for and your employer. :)
He said in the beginning that those are for figuring out whether the interviewer should invest more time in figuring out whether you're fit for the position.
These are the sorts of things you should kind of be expected to 'know in your sleep'... They are easy weed-out questions. If there's something there that you could not answer, then there's no use in continuing talks.
Love the video, great review of the core basics :) thank you for making it! Have an interview for an Admin Position tomorrow and this was very helpful :) 10:15 You could add regex to get rid of the 'grep' in the output #ps aux| grep [n]ginx I'd also recommend pidstat for cpu as well & apropos to go along with man
Thanks! There were a number of questions on DNS & MySQL I wasn't fully prepared for, other than that everything went well I think. Thank you as well for all the great content & replies to posts :)
After he types the command and the results are generated, at the bottom it shows the command that he just ran "grep". The command itself "grep nginx" got placed in the results. Adding the [n]ginx would in essence accomplish the same as "grep -v grep" as it would exclude grep from the output. If that makes sense. The only reason I suggest it is sometimes it can throw you off when you're looking for specifics, such as a number of processes or something to that effect
'info' is another good source of, well, info, lol. The best comparison I've seen is 'man' provides a cheat sheet where 'info' is more of a tutorial, the problem being that an 'info' page isn't always available. Works better with newer commands, if the command you're working with doesn't have an 'info' page it will default you to the man page though. Info doesn't install by default in all systems but I'm pretty sure it's in most distro's repositories for install.
I find it funny that with 28 years of linux experience, 25 as a professional linux admin/engineer I still get asked some of those questions.
Though the funnest one I have had was an interview a few years ago. I was asked how I would stop an HA pair that when booted was caught in a boot loop. System A boots and forces system B to reboot, then system B forces system A to reboot, etc.
I asked which version of Linux they were running and the Tech responded with RHEL 5.5
I let them know that there is a bug in 5.5's init setup. On a default install the ntpd service starts after the HA services. That time jump causes it to fence the other host and reboot it. You can fix it by changing the ntpd service to start before the HA services.
Next thing I know, I hear lots of typing and the tech says "Holy cow, he's right" The manager then tells him to get the change notices in so they can fix the issue once and for all.
I asked when I could start and was told they had other to interview and would be in touch.
6 years, Im still waiting to hear from them. lol They never contacted me and never responded to emails after the phone interview. It just reinforces the old adage, if you know what is wrong dont give them the solution!
Grandpa's Place Whoa. How the hell weren’t you hired on the spot? Clearly you had more domain knowledge than any of their staff!
Daniel Livingston Probably the Guy on which he was speaking to, just gave himself the originality of credit .. (he said that it was his idea).Said to hear that OP got fooled
Integrity isn't dead, but some organizations work hard to kill it. Consider it a gift from God that you didn't get the job in that snake den. Thank you for sharing the tech tidbit and retrospect.
Grandpa's Place "with 28 years of linux experience"
I believe Linux was first released in late 1991. You must be from the future.
Grandpa's Place Ok :-)
Dropping a comment to let anyone who is watching this in 2022 that this is very good information. Just had a tech screen today which asked 6/9 of these questions.
I usually check with my fingers. If one goes in, the port is open.
That is not linux which you are thinking aboujt.
and if you get a shock then you know the port is up and running
good one.
you will got the job, instantly.
Funny. Security will show you out.
netstat tulip works for me :) ..my wife is Dutch
I've been a linux admin for 20+ years (originally as my actual job, for the last ten years purely for my personal stuff) and saw this video and watched it on a lark. I honestly expected some cringeworthy content - but was pleasantly surprised to find that it was all good basic info, presented fairly well (obviously VERY basic, but given its target audience that's fair). I would add only one thing, to the "listening network sockets" question: lsof -i can often be more useful and easier to use than netstat.
I think lsof -i is better as well since it's compatible with Unix and Linux. netstat -tulpn does not work on Macs.
Just watching this to get better at home use xD
Same
Same
Same
@Unbekannt I nouveau r heard this pun
Linux noob here
I always remembered netstat - tulpn as netstat -tells u lotsa port numbers .
I mean totally beside the point but who doesnt love fun anagrams
I like this. I will use this. Thanks buddy!
I know a system admin that always type in "netstat -plant" or "netstat -plantu". I have muscle memory to always use "netstat -natpl". And I always use "ls -alF" via muscle memory.
i just type netstat -tulpan because "tulpan" is actual word that one can easy remember
You could always run nmap. It'll tell you open ports on yours and other systems.
ty
Recommended book:
"How Linux Works. What every superuser should know" by Brian Ward
It's the best.
Is it open source?
I'm an advanced linux user and administrator. Using linux both with my work and full time on my private computers (I've ditched Windows and Mac OS X completely). I already knew the answer on all those questions. It is a well done video, bringing up the basic questions one would actually asked in a linux job interview.
One thing to be prepared for, in such an interview, is to be ready to answer "I don't know ...". Some ask tricky questions that is hard to answer without knowing the companies computer/servers in detail at first. Questions only a person hired at the company would know.
They ask these kind of questions to see if one is capable of a "I don't know. Let me find out.", or if one is more like a person who tries to blab on about things one don't know anything about.
When you get those question you can never go wrong with the simple reply "a hammer"
Your interviewer will not like an I don't know answer as to them that sounds like your just giving up. They want to know what you would do to try to trouble shoot the issue. For example start asking them if the servers are on the same local network or across a router and verify if the routing tables are jacked up etc. They want to know what your ability to troubleshoot and solve problems not drill you for rote knowledge,
@@carlosgarza31
That depends.
I think that it is a completely false notion that people expect you to know everything (because the reality is you can't know everything, although that shouldn't stop you from trying), and if someone EXPECTS you to know everything (again, depending on what it is), then I'm not so sure that I would want to work for that person or that company.
Either they should be creating an environment from which you can grow and learn (and invest in you as a human resource) or they're expecting to treat you like a trained monkey and ONLY do what they tell you to do and nothing more/nothing less.
Yes, there are basic aspects, and even some intermediate aspects to a person apply for a job, but I usually will ask someone a tough, challenging question, preferably something that they haven't seen or dealt with before, because I'm looking to assess their problem solving skills, not how well they can memorize stuff and ONLY execute the stuff they've memorized.
If all you're doing is like basically the human version of a digital janitor where all you're doing is just cleaning up someone else's stuff, then fine. But if I want you to actively be able to solve problems - both foreseeable and those that were unforeseen, then your memorized scripts and procedures may not work and I need people who can solve problems AS well as being a "digital janitor". (Heck, a "smart" digital janitor would automate the job for themselves so that they can do other things that they want to do.)
Linux is AWESOME!!!! ....when it works.
@@ewenchan1239 I think its more fair to say usually the interviewer for what ever reason assume they know more then the applicant. I see it in my coworkers all the time when they grill applicants.
Commands to Know: uname -a / ifconfig or ip addr show / df -ah / service status or systemctl status / du -sh code/ / sudo netstat -tulpn / ps aux | grep or top or htop / mount /dev/sda2 /mnt or mount / man / / Google & others
df -a --si
In an interview you should begin the answers with something like "I would do it with ...." because there are multiple ways do do stuff on Linux and it will show the interview partner that you're aware of that ;)
This is good advice; thanks!
Hey same goes for a c++ job.
Did this. It didn't work for me. Asshole asked the dumbest questions. He didn't ask any of these!!
@@SlickBlackCadillac can you share what he asked from you?
From one sysadmin to another: Kudos on showing the modern equivalent to these commands! I feel like a lot of tutorials cover only the old way of doing things, which is quickly going out of style on recent linux distributions.
There is one I would like to add: "ss" seems to be replacing "netstat" nowadays, though the syntax is very similar ("ss -tulpn" works as you would expect).
Sometimes useful for when you don't know what commands are associated with what you're trying to do is "man -k whatever". What you're looking for may not be there, and if it is then there will probably be also all sorts of other stuff that isn't what you're looking for, but sometimes it pays off. I tend to use it before resorting to google, simply it's easier to wade through the results.
If your - key is broken, "apropos" is a synonym for "man -k". Which, of course, you knew because the first thing you do with man is "man man" :)
Thank you. My name is Frank Ayerdi and I am in Linkedin. I am teaching my 9 year old Linux and he now has his own computer. I found your video very helpful.
Netstat got replaced by 'ss', but parameters are same: 'ss -tulpn'
I don't care about the questions, but the little idea of putting my name into config files I chanced to be sure to find every single on when migrating might just have changed my life!
I learned that the hard way ;D
What do you exactly mean?
I've switch to have a version control on config files, rcs, svn, git or whatever
I learned that for the "ip addr show" command you only actually need the first letters. Just a little time saver. Example: "ip a s eth0"
Yup! In most cases I just do: ip a
I prefer good old ifconfig because that one will also work under non-Linux systems where "ip ..." won't
Sounds familiar, IOS anyone?
I got them all too, except I said nmap instead of netstat, netstat for local, nmap for remotes.
Linux user since 2010.
I did the same thing. I also just learned about du -h.
hehe same, got all but netstat, using linux since 2013
Same, but I don't think nmap would be counted as incorrect.
nmap and netstat should really both be accepted answers. But as an interviewee I would mention netstat also and see if the applicant is familiar with it.
Ive come from business area, entire life work focusing on finance and then, BANG, my boss sends me to IT area.
I have to confess I used to read hardware books while on graduation just for fun and that I always wanted to know more about Linux since I was a kid and had read about hackers and stuff.
But damn, boss had gave me an opportunity to focus on another area and I had to run to learn more about it.
Got my Comptia and LPI certifications on Linux, studying for RHCSA and doing a course on oracle.
Gota get some more certifications or my short time working as sysadmin may be frustrating in the near future =]
Working in IT since 2015 and in love for Linux =D
Nearly all of these questions came up in my last Linux Sysadmin job interview. I can likewise confirm that these questions are pretty typical.
David Sebastian likely your interviewer was trying to find some interview questions from TH-cam,lol
As a 15 y/o, I have used Debian based systems for almost 2 years and I can answer all of them. They don't seem that hard, but is this really it about being a sysadmin? There must be more to this than that.
Well from using Linux since the 90's as a personal thing. I guess if that's all they wanted to know then I could easily be a sys admin for a living instead of just as a hobby.
@@yatoxic1213 these questions tell if you have very basic Linux knowledge. It's like asking a car engineer "how fast is the car going" "how much fuel is left" "what gear is the car in". I can imagine one or two of these questions being asked in the beginning of the interview in order to make sure nobody is wasting time. After failing to answer, the interview is over and if you got them good, the interview will start and you'll get proper questions based on the actual job you are applying for.
@@MennoSchepers that makes sense
I had my first ever interview today for a junior linux sysadmin, about 4 of the questions from here where asked.
a few more include; how to compress a log file, config file for kernel, how to ssh into a server when the server is down. i was so nervous, i did not make it to the next level. I have another interview coming up in a couple of days, still nervous, but working harder.
Congrats on interviewing! Don't worry about the interview stress -- it will get more and more manageable with each interview you do. Just focus on why you love this stuff and ask interesting questions about the company/work environment. Wishing you luck.
I watched this video before some months, I didn't knew most of the staff, after 6 months of reading and experimenting with vms I know almost all the answers, great video!
I was once asked to write, on a blackboard, a firewall rule using iptables, as part of the job interview. Was a very pleasant interview, because I totally didn't expect these kind of questions and it shows what kind of employer you're going to get. It did however inspire me years later to create a 'broken' Linux system and have new colleagues try to fix as many problems as they could, in a specific amount of time. It tells a lot about the person. Not many people can fix "the chmod binary is set to non-executable" problem without resorting to Google for the answer.
I've looked it up, thanks for sharing such things, the easiest way I found was to copy another executable file to the original file as this will inherit the +x flags.
I'd bet that even fewer people know how to set the various permission flags independently and separately for each user.
Only yesterday I was asked #1 question on the interview...keep doing what you doing...it helps a lot of people out there.
I'm just a home user, and I got all of them. That's a nice ego boost.
Nice! My kind of user :-D.
i got 2/3 out of 10 and considered myself pretty good at it. lol
lol same here
Same here. If someone can`t pass this with education they chose, then they deserve to flip burgers for rest of their life.
Same. I'm thinking of going for RHCSA certification as soon as I finish with CompTIA Security+.
I remember watching this probably a year or two ago and writing everything down and thinking to myself that I’ll memorize everything and be golden. But what you said in the beginning is right you gotta use it before you even know why it’s there in the first place. Well now a year or so later and I can answer all of these questions truthfully and give you exact reasons as to why I know the answer to each of them. Thanks for the video it taught me a lot and prepared me for what is to come!
Sounds like you are on exactly the right page-it’s the experience that matters, and puts all of this into context. Cheers!
For dealing with mounts, my favorite command by far is "lsblk" because it shows all your mounted and unmounted devices in a very neat and readable manner. Kind of like a well formatted version of the command "mount" (only if you're using it to display info).
Same.
lsblk is more readable laying down better the info, i would had used it too.
df -h doesn't take root-reserved space(usually 5%) into account, which is why the actual free space of the shown root disk is a little higher. .
This is a great detail to point out for others here; thanks!
I wouln't take that 5% for granted as when your disks user space fills up your system will be so damaged the only one that will be able to login at that point is root in single user mode most likely at that point. Certainly user level processes won't be able to do anything with it.
so? you make an alias like this: alias df='alias --sync -ha' then EXPORT it or save it in your .bash_aliases file .... then logout / reload your shell.
Bingo or voila. it now SYNCS all the HD caches before showing you the latest stats.
Df -h also doesn’t work very well if you’re using zfs with bunch of snapshots. I like to use “fdisk -l” for this reason (though it’s quite verbose)
I had to use Linux in some of my courses and I learned more conceptually from this video than any of my professors. I understood everything you covered and then some, but the way you explained it filled in little gaps in my knowledge. I never knew "htop" was a thing. Just top haha. You got yourself a sub.
Instant fan.
Practical. To the point. Well explained. And I'm able to follow along in my terminal without pausing.
Good stuff.
.
Them: "How do you check for open ports?"
Me: "nmap."
Them: "Well yes, but actually no."
nmap is what I'm using for some reason even though netstat is there
@@gluttonousmachina2961 nmap wont nuke your open ports lol....
I'm running arch and netstat isn't even in the repos.
@@defalt2384 your comment is accurate
@@defalt2384 net-tools is deprecated. What should I do?
Tutorial Linux, I just want to thank you from the bottom of my heart as a 2nd year transferring to another school as a first. I could hardly grasp shells and grep, most specifically assigning access for different users/groups. I really appreciate the head start that you give guys like us who want to find a passion for networking. And I'm not going to lie the language barrier was really killing me, I can work with what I got but your voice sounds like angelic hz
Here's a few I ask:
1 - How do you add a new disk to a linux VM (typically) without rebooting?
2 - How would you go about recovering a root password that you don't know?
3 - Why would a file system APPEAR full even though a "du -shc" shows that there's not that much space taken up?
4 - How do you add space to an existing file system in LVM?
and to see if the candidate has any network debugging experience:
5 - You've got a DNS server that's one router hop away on the network but you can't do a zone transfer. What are some things you'd check?
Those are some great questions, thanks for sharing!
@TutoriaLinux heyas thank you for this video! I can't believe these are questions to a job interview because they're so easy and it's basic stuff. Coming from an ex windows power user I am completely in love with Ubuntu linux and I will always remember these important commands. Thank you!
...and I felt so good about myself (about a decade of exclusively using Linux at home, no professional experience at all) getting a 9/10 on the original list of questions (forgot about netstat as that too I never need at home)...your list I would fail horribly as none of that I have ever come into contact with at home. At least you gave me something to man/google...
How would you answer these questions?
of those, i need to learn: 1,2,4,5 but answer to 3 is just simply this (in non tech or CLI terms): SLACK space and the structure of the formatting used on the filesystem in question :) and was there compression or no?
Yay I passed round one. Those two years working as a support engineer weren't wasted :D
Just completed an interview and did amazing after exploring the information from this video! thank you!!!
Woohoo! Congratulations.
@@tutoriaLinux hey man is there any place I can donate to your page or something? I just bought the course on Udemy and look forward to learning even more.
I'm a big fan of putting time stamps in the description for each topic. Thanks, and nice work!
Thanks. Gotta start doing that again; it's super time consuming but I'm glad someone's using that feature :-D.
Professional Enterprise Linux instructor here. I watch videos like this mostly for laughs because they usually feature someone who is trying desperately to make up for lack of true understanding with confidence. I kept waiting for you to say something stupid or completely wrong, but it never happened. You answered every question almost exactly like I would have.
If it's worth anything to you, you've definitely got my seal of approval!
I wish so many computer people weren't like you.
@@ciscornBIG yeah, guy sound like a prick.
Thanks a lot Dave for these super videos. I went through all of them in the "The Linux Basics Course: Beginner to Sysadmin, Step by Step" playlist and you rock !! I Learned a lot more to move in the Linux world as a Sysadmin. Thanks again !!
I'm just a Linux hobbyist but I found this interesting and I am going to learn more from here. Thanks for posting !
For me it is so much more important that some one understands what is actually going on with the system architecture and how it all fits together rather than memorising commands and syntax. Most things asked here can be done in a variety of ways.
2:50 - checking IP address: ifconfig is deprecated since 10 years already. You should use 'ip addr show' or 'ip a s' for short or even 'ip a' shortest version. Latest linux distros doesn't even ship with old net-tools which contains 'ifconfig', but they ship with iproute2 which contains 'ip' command.
Also: old 'ifconfig' doesn't show multiple IP Addresses on single interface which 'ip' does. And this is different than interface aliases.
Same with 'netstat' vs. 'ss'.
9 out of 10. Services got me.
But like me, you have learned something new.
You can also use hostname -I (capital i) to list all the IP addresses for a host (omitting loopback and link-local addresses) - easier than trying to pick through the output of ip a. As others have pointed out, ifconfig and netstat are deprecated, and have been for a long, long time. RHEL7 / CentOS 7 has already dropped it from the base install, and the Debian people are working on it.
I learned half of these installing arch last week 😂😂😅
I never, ever ask technical questions when I interview. People are super nervous and can always forget names, etc. Better to actually watch them do it on a machine.
'How to ask questions the smart way' is gold. Been a while since I have seen it mentioned. Shame it hasn't been updated in nearly a decade. Having said that, a lot of it is timeless wisdom needs to be read.
As registered Linux user #3406 I could answer all questions, just some with the older commands :-)
oh .. I forgot to refresh this registration. but why does "linuxcounter.net" now point to a transgender website :-D
Now i'm thankful to my 5th grade teacher he told these and also gave us lessons for typewriting. These are essential skills even if you are not into IT.
Interviewer: "How would you [some task]?"
me: "I'd search online, because that simply is the most effective method"
what if you dont have network?
@@pavloskairis9994 It probably wouldn't work in a job interview, but I would've called someone who did. I'm really good at searching for solutions to problems, so I'd ask them to search using my search term. I'm well versed enough in Linux to only be told what the commands and stuff should be, so they'd only have to read what they find.
@@pavloskairis9994 On my phone? How?
That’s the answer I use
No. _Knowing_ what to do is the most effective, nothing is faster than that. No one wants you sitting around googling things you are supposed to know by heart while your client is dead in the water and losing money with every minute of downtime.
P.S. Of course you can't know everything, but if something comes up often, you should know it.
Novice Linux user playing with Linux. Though these are interview focused, they helped me get a quick transition view and calls to investigate further. Thanks for sharing!
Thank you for this - this confirms that I am studying the correct information. I would have been able to answer all those questions intelligently, adding "info" to #9. Example how would you look up information on something you you don't know? I'd answer "man or info - into gives the same information presented in a different layout".
Agreed. Usually info contains MUCH more info about like how the program actually works rather than just how to use it which is what man is better for. For example the man page for "make" will just simply show you how to use the make command, but the info for "make" is extremely detailed and helps you with writing makefiles and shows you how they work.
I learned 2 things more: htop and mount (status only). Thanks, man!
9:57 "pgrep" or "ps -fp $(pgrep ...)" can be more useful instead of "ps | grep" in case a server runs a lot of processes and it's very slow due to overload
@10:09 Tip: to see the headers when inspecting `ps aux | grep ` you want to egrep one of the header columns, e.g.,
`ps aux| egrep "systemd|PID" `
net-tools is depreciated you should be using the iproute2 package aka 'ss' instead of 'netstat'.
It's good to know both. net-tools will be around for a long time on Debian, CentOS, and RedHat servers that new sysadmins will maintain. You're absolutely right, though -- I should make a few videos covering the new iptools suite.
Tegan Burns Linux has always and will always have many ways to skin a cat, if it's available use it.
lsof -Pni
ss seems to be messier. makes it kind of annoying to read
I work in a big governemental agency in France and we've got more than 1500 linux servers in production. Versions are redhat 5, 6 and 7. Your advice does not apply for RHEL5. RHEL 7 is systemd while 5 and 6 are classical SysV. One must know both versions.
Here's my answers:
1: ls -l /vmlinuz (Yeah, i know, pretty dumb method, but it works)
2: in Bash or in X windows?
3: df -h
4: I'll have to google the command first
5: du -h
6: Google for the command, again
7: ps aux | grep
8: sudo mount /dev/sdx1 /mnt
9: If I don't know the command, google for it. If I look for a command, which command. If i don't know how to use a command, command --help, or man command
10: Just google it. Most likely someone has already asked the question before, and got an answer
Great, practical explanation. Very helpful in preparation for a linux interview I have in a few days.
Thank you very much for a clear and concise list of Linux commands! Cheers!
Pretty fun as a quiz, got them all except netstat, I would use nmap, and I would have to look up its arguments - I don't use the functionality often at all.
With the "how would you mount a usb drive you had just plugged in" I would add "dmesg | tail" to get the device name first.
lsblk
blkid so I can see what kind of file system and the UUID for mounting
No frills and nothing boring. Everything important. I dig it.
1:50 How to the check the kernel version of a Linux system
2:50 How to check the current IP address on Linux
4:03 How to check for free disk space in Linux
4:55 How to see if a Linux service is running
6:33 How to check the size of a directory in Linux
7:02 How to check for open ports in Linux?
9:48 How to check Linux process information
11:49 How to deal with mounts in Linux
13:51 Man pages
15:04 Other resources
I'm a hardcore IT Engineer with Linux experience and you're brief tutorial on Linux was helpful and informative. I don't pretend to know all their is to Linux and I don't know many IT Engineers that do since Windows has made most of us lazy, although I've rediscovered Linux for my interest in web development and I've gone too long without a dedicated Linux Server in my home office. Subscribed and Liked plus I intend on checking out all of your videos since Linux has come a long way since last I played around with it.
you make this so much easier to understand and very clear.
thanks so much
Watched this 4-5 years ago when starting out on linux for the first time and today will be the second time for a job interview.
Yes! Good luck!
@@tutoriaLinux Went alright thank you very much :)
I literally have a written exam in 2 hours and I am sitting here watching this instead of going over my material.
I study law...
You should be familiar with Linux if you wanna grow as a lawyer, it's common knowledge mate.
We actually had a former lawyer doing linux admin stuff on my last team. He said he switched careers because he likes helping people.
maybe he is planning on suing for software copyright infringements
@@datasdawayilikeit8683 nah just procrastinating tbh. But thanks for your trust haha. Copyright law is probably interesting as well.
@Wandy Wexler Weslon Can't remember exactly which one it was but it went well iirc. Thank you for asking haha.
I know most of this commands because of work, but the way you explain this made me subscribe without hesitation
if these are the commands for admin then almost every Linux user is an admin ;-)
I mean, you kinda have to be, you're an admin of your computer ;)
Did 750 trolls just decide to dislike the facts of basic Linux SysAdmin tasks? 🤷🏽♂️ … nice refresher, and all essential
7/10, Surprisingly easy for someone who just copy-pastes everything :(
Good video for beginners. I'm not a systems admin but I've interviewed for such positions and almost never get asked these questions. I usually get asked things like, "How do you find a failed disk in a raid configuration" or "How do you spin up a new virtual for load capacity" and weird stuff like that.
Agreed, I am in no way a linux sysadmin, but I can do some stuff. I use google to help with errors. These questions seemed so basic. I had a Magento site which a hosting company's admin could not fix a problem with a php error. I later found it was related to the permissions of the files, but once I upgraded to a more recent php verison it was rectified. I was surprised their admin was unable to easily fix it.
I feel the urge to just answer the question in the thumbnail: I would google how to open the ports.
Hah, I love this.
FYI. I’m a network engineer and I got 10 out of 10 correct. Experience counts for a lot in this world. :)
Great to refresh a memory on some of the commands, thanks!
i never pursued a certification apart from my associate degree in IT. but i’ve used tons of linux distros and the last 4 years i’ve been using only fedora. and i kinda knew like 8 out of 10 here. still this is really informative and good to know as reference material. specially if not used on the daily.
I thought I was OK at this. I was not 😂
Thanks for the helpful video!
it's been a year since my first comment a year ago, I already got a whole bunch of these questions on multiple interviews. Now it's coming in handy.
Appreciate it! I can't even count the number of angry comments I get about these questions, but the reality is that they STILL show up in a huge percentage of interviews. I suspect they'll be around for a looooong time.
amazing !!! thank you ..all of these questions are asked in my amazon interview.
Can you share your experience of the Amazon technical test please. What all questions are asked if some has applied in AWS domain.
Other questions are: how to reboot a system without everybody shouting at you, how to know who else is connected, how to make a backup and how to restore, how to synchronize systems.
I loved the advice not to fake knowledge! I was often very much pissed, because every interview is taking time and preparation. I do not require top gun system operators, but if you hire one, you want to be sure they know how to move on without destroying a server or system.
I always read fstab as F-stab rather than FS-tab for some reason.
Too much dealing directly with end users can lead to wanting to f-'ing stab them...
I also read it the stabby way
I read it as FS-TAB because I believe it basically stands for (F)ile (S)ystem (TAB)le
I wonder what psychological deviations that implies.
Same!
apropos to find occurence of a text in all man pages. Ex: apropos disk usage
Finished watching 54 videos, thank you very much
@tutorialLinux : I might be mistaken but I think you might be confusing the role of 0.0.0.0 in the local and foreign address columns. as far as I've understood it, in the local address column it means "any of my own IP addresses" in a scenario where you have multiple. Let's say for example you are in 2 LAN's and you'd have 10.0.3.1 and 192.168.3.1 assigned to the same machine: clients can connect to either, and they will see an open port 80. If they want DNS (port 53), they will get that service when connecting to the 10.xxx address but not when connecting to the 192.xxx address. In the foreign address column, it means "Any external IP address" which signifies the IP (or subnet) of the client connecting to you. Please correct me if I'm wrong, but that is how it was taught to me.
Yep, that was a pretty dumb miscommunication on my part. It's "all of my IP interfaces," not just "all public IPs." The reason it came out of my big dumb mouth like that is because just before filming this video I'd been doing a bunch of nginx config stuff on some servers with multiple public IPs (trying to get the right website configs to match the right ip/server_name combinations) and only had public IPs in my head. Thanks for pointing it out!
ps aux | grep [n]ginx
this way you don't get the grep process in the output
or use grep -v "grep"
@bbababonbon..bonfire!
not really efficient
Depending on what you're looking for, pgrep could also fit the bill, e.g. "pgrep -a sshd"
PS fax | grep nginx ll give you everything you need to know abt nginx process
I recommend ps -fC
All this works also on macOS. Nearly everyone can learn that on-the-job if needed. I would ask other questions. For example how you find answers if you don't know something. Etc.
Google it.
How are you supposed to become a junior linux sys admin if you are exactly that - a junior in your career with most likely no profession experience? Where is the step from no professional experience to professional experience, if every company wants you to have X many years experience, even for a junior role.
I think job ads generally tend towards being stupid and misleading. Most have been either created or severely edited by an HR person who has no idea what the job is actually about. Every IT job I've ever had required a College Degree (which I don't have), according to the job description. Every one of those companies has been open to self-motivated juniors, which is how I got started. As soon as you talk to an actual technical person, it's about demonstrating that you've got the skills you need to be useful right away, that you've got the motivation to learn and improve in your spare time, and that you've got the proper personality and instincts to keep from screwing up too badly (caution, double-check mentality, good writing skills, social skills, patience, lack of arrogance, etc.). Nothing in a job ad is carved in stone. Apply anyway and make sure you have a good story about yourself and your background, and sooner or later you'll get a chance.
Very true regarding flexibility of job apps. However, as you say when you have HR people editing and often recruiting for these jobs (who may not be very informed about the role) you often have those same HR people initially sifting the applications as a first round. The issue I found is that I wasnt even able to get to a stage to prove myself by answering questions like this because, on paper, I didnt appear to match requirements. To explain, I do a lot of sys admin related stuff in my spare time. None of it is paid, its all for fun/to help community's I am part of. However, because it lacked the word *Professional* this experience didnt hold any value to the initial interview sifters who rejected me. After asking all of them why, the ones who replied said it was due to "lack of relevant professional experience". I also find that it is very difficult to prove that you are motivated and willing to learn if you have no relevant experience on a resume , especially if your resume is the only factor in your initial application process (which it is 99% of the time).
Yeah, what you're saying is absolutely true in my experience as well. The way I found around this was to target small companies (~20 people) that weren't big enough to have HR drones, and then apply for internships and junior roles at those, using super customized cover letters. After applying, it might be worth it to contact the hiring manager (company tech guy, at a place this small) directly and give him a 10-second version of this story (applied, worried I'll get sifted by HR before I can prove myself in an interview, love your company and wanted to ensure I get a fair shot).
Also, it might be useful to rebrand your community volunteering as "Open-Source" work, if there's any way that might apply. If not, consider writing some scripts or programs to help automate your volunteer work there, and put them up on Github. HR drones learn slowly, but "open source" is a word they are starting to recognize.
Both of those are really good suggestions!
+CardinalHijack As Dave hinted, you must become "creative". He suggested shoehorning "Open Source" in there. My relative called years of unemployment "working in import/export overseas". So whether you outright lie or just "re-interpret" your experience (because you do have experience -- its just not professional (read: paid) experience) your goal will be to get past the gatekeeper and force them to see how good you really are for the job. And sometimes that means... "exaggerating". Good luck!
I like the fact that I got most of them right and only got into linux last month or so.
I'm not a total noob, but it's nice to see that I'm trying to learn more "advanced" stuff from the start :)
but then again yesterday I was at a lost and literally caught myself googling (out of frustration) "how to pin linx!".... 2-3 minutes later I realized I forgot to plug in the cables :)
My soft setup was fine, just that I forgot that I was testing redundancy and "accidentally" unplugged both ports.
Haha yes! These are definitely basic phone screen questions (not enough to actually qualify someone to *do* the linux/infra/devops job), but they're still REALLY popular filters. 90% of applicants can't answer them.
Thanks for this, it's very useful! :) Luckily I knew all the answers (with a short hesitation at netstat). Though I'm more into programming than system administration, I use Linux because it's beautiful! I'm about to finish a huge book on C++ this or next month and then I'll see what the market has to offer and what's next maybe Python or D.
I use a lot of Python (excellent for job prospects), but D is a *really* interesting language. I'm far from a pro with D, but it's definitely an interesting one to learn. Again, if you're about to engage in a job hunt, Python will probably be a better time investment in the short-term, though :-).
I did Python before C/C++ and Java and it is much easier, first time hearing of D
Very nice refresher for me. A few I didn't know or forgot completely.
IMHO questions that can be literally googled in less than 30 seconds should not be a deal-breaker for interviews.
Great video! I am 19 years old and started working with Linux about 3 years ago, was happy know the commands you used and understand the explanations you gave.
Hey there! Sweet! Short and to the point. Thank you for the work and the knowledge sharing! Keep it up!
Thanks for this. I've been a mostly Windows Admin. My linux experience has been limited to playing around at home. Although, I have used all of these commands in the past, a few did not come to me fast enough to impress at an interview. Most were "dammit, I knew that". Guess it's time for refreshers.
Another common questions asked is where are logs stored: Basic answer is var/logs
# journalctl -f -u
to see service log
the pound symbol means that you need to be root or run with sudo
in the shed
Great video tutoriaLinux. I was surprised by number 10 however. Many developers(most?) include both a man page AND an info page. Usually if there is only a man page, the info system will just display that. The info page can go into incredible detail about how to use a program - including tutorials. Also, showing these two commands would have been very helpful to people just getting started: "man man", and "info info".
Yeah, I need to do a new (and better) video on where to find help/resources/docs. There are so many great resources I haven't yet mentioned in any videos. Just gotta find the time...
Well I learned something new, so I'm not complaining. For 22 years I've been using "du -h" or "du -hc", and being annoyed by the output... If I'd only read down to the -s section... So, thank you - I subscribed - looking forward to watching your old and new vids!
The video didn't let you answer question 10 as he was already answering "google stackoverflow etc" etc the second it appeared.
OK, without watching the video I'll see what I can recall from memory to answer the timestamps
1. uname -a
2. ifconfig
3. df -h
4. htop? netstat? sudo service something status
5. df something
6. netstat something localhost
7. htop
8. /etc/fstab?
9. man something
do i qualify to be jr. sys admin now?
I feel like these aren't even jr. sysadmin, these are just linux user level... Though it definitely weeds out those who are utterly useless for the position (remember, this is just phone screening).
Yep, that's exactly it. These are some of the most popular *simple, basic* interview questions I've seen/used, precisely because they can save a huge amount of time by weeding out candidates that aren't competent with a wide variety of the basics.
As you pointed out, KNOWING THESE DOES NOT MEAN YOU'RE READY FOR A SYSADMIN GIG, BUT *NOT* KNOWING THEM DISQUALIFIES YOU IMMEDIATELY. There are scores of people who respond to job ads who can talk a good game about scaling, best practices, pros and cons of different products, behavioral questions, and more. A huge percentage of those people then proceed to blow every single one of the basic questions in this video.
These questions are a great way to avoid the sysadmin version of "architecture astronauts" (a popular term in software engineering), who can tell you about design patterns and computer science concepts all day long and then fall down when they have to write fizzbuzz (google it) or similar ultra-simple programs.
Well, you haven't *disqualified* yourself, which is exactly the point of these questions :-D. Answering these (along with about ~20-30 minutes of more open-ended troubleshooting/experience-testing questions that aren't in this video) would at least keep your resume from being thrown out.
:(
:D 10 out of 10. Totes patting myself on the back, lol.
Great video. Also want to point out that for number 10 you can use help flags such as: "--help or -h" for most commands. :)
Just downloaded my first linux distro and have no clue what you are doing, but it looks interesting xD
How's the journey going?
@@p5eudo883 Accidentally fcked up my manjaro and now I am fiddling with a timeshift backup that just doesnt want to work xD its a strange ride but I´ll get there ^^
@@flyfight98 I first started learning about Linux back in the 90's in HS. Messed up, learn how to fix, and learn why not to do that again. All part of the learning process :).
awesome
I've heard of most of these but I guess I have to put them to memory better. That's a good reminder if I ever wanna be a professional sysadmin.
Are you sure these interview questions? They seem way too basic/easy.
It says Top 10
Adi Serghei Most employers want to make sure you got some experience, so it's not mandatory to have super hard questions, but the difficulty will vary, based on the position you are applying for and your employer. :)
He said in the beginning that those are for figuring out whether the interviewer should invest more time in figuring out whether you're fit for the position.
These are the sorts of things you should kind of be expected to 'know in your sleep'...
They are easy weed-out questions. If there's something there that you could not answer, then there's no use in continuing talks.
@Adi Serghei these question asked during the phone screening to filter out people that don't use linux at all. Linux user since 1994.
Love the video, great review of the core basics :) thank you for making it! Have an interview for an Admin Position tomorrow and this was very helpful :)
10:15 You could add regex to get rid of the 'grep' in the output
#ps aux| grep [n]ginx
I'd also recommend pidstat for cpu as well & apropos to go along with man
Nice suggestions, those are all good. Good luck on your interview!
Thanks! There were a number of questions on DNS & MySQL I wasn't fully prepared for, other than that everything went well I think. Thank you as well for all the great content & replies to posts :)
what do you mean to get rid of the 'grep' in the output? he typed exactly what you have shown.. 'ps aux | grep nginx'
After he types the command and the results are generated, at the bottom it shows the command that he just ran "grep". The command itself "grep nginx" got placed in the results. Adding the [n]ginx would in essence accomplish the same as "grep -v grep" as it would exclude grep from the output. If that makes sense. The only reason I suggest it is sometimes it can throw you off when you're looking for specifics, such as a number of processes or something to that effect
'info' is another good source of, well, info, lol. The best comparison I've seen is 'man' provides a cheat sheet where 'info' is more of a tutorial, the problem being that an 'info' page isn't always available. Works better with newer commands, if the command you're working with doesn't have an 'info' page it will default you to the man page though. Info doesn't install by default in all systems but I'm pretty sure it's in most distro's repositories for install.
13:58 #9 "I usually ask an interviewee"
I don’t usually comment but i found this very helpful and stumbling through your playlist for Linux beginners is a gold mine. Respect!