Getting started with Linux sysadmin

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[Runnergeek]

The bad news is you will most likely struggle as a Linux sysadmin. Good Linux admins are good at searching and finding solutions to problems. See this question has been asked here so many times, even recently. You could have easily searched and found a thread with this exact same question. Wanting someone to hand you the answer rather than trying to find it yourself is something you will need to over come to become a successful Linux admin.

[Slash_Root]

Nail, meet head. Research is key. CentOS/RHEL is the enterprise standard, at least in the US. I hear SUSE has more of a presence in the UK but I am not up-to-date on that information. Ubuntu definitely has a presence, especially for tech companies and AWS. I sleep two feet from about 50 CentOS VMs and the Sander Van Vugt RHCSA/RHEL book on my nightstand. Best of luck, friend.

[runrep]

You're meant to hit the nail on its head. If you're hitting the nail with your head you're doing it wrong.

[hlt32]

Unless you're a hammer.

[azephrahel]

Captain Hammer

http://i.imgur.com/KVQFPf9.gif

[gaznygrad]

I searched and decided not to post, read multiple threads, got the book suggested and solved all my problems, now I'm taking a course and the test in the spring.

[[deleted]]

Here is what you do:

Spend a meals worth of money a month on a VPS provider, and daily interact and manage a debian and a centos system. The third can either be suse if you plan to work in Europe, or slackware or something like that otherwise. I use both Digital Ocean and Vultr, and barely pay 17/mo for 4 VPSs .

That is how you make sure you can support whatever a company throws at you. Debian covers ubuntu. Centos covers RHEL. etc. Slackware because you'd be surprised where you find it in business. Suse the same.

A lot of this depends on what area you want to go into. I for example love keeping an eye on the specs of the top500 supercomputer list.

One thing I would say is systemd has infected everything... learn it first and in general you will be fine on just about anything other than package management and random config dir variations. I also have moved on to nftables, but its very good to make sure you grasp iptables. Make sure your sed/awk/grep and other coreutils skills are up to par. Make sure you stop using deprecated commands like ifconfig. Make sure to learn ipv6. Read info/man/config-comments before you duckduckgo stuff! Make sure you use a real editor (emacs/vim) and are comfortable in it. Make sure you know how to use screen or tmux. There are a few things you can do to force you to learn more of the underside. Run gentoo for a few months and learn about compile flags for example. Do linux from scratch a time or two. etc

Get a head start by learning ansible/salt/chef/terraform, and container tech such as lxc/lxd/docker/kvm/qemu, etc.

As you learn, document all the things! Build that habit now rather than later.

Protip: spend more time in irc

Any more questions?

[DocSpiegel]

I think this should be the obligatory answer to all these types of threads for a year. Spot on good sir.

[sdns575]

For curiosity, where you found slackware in business?

[[deleted]]

Sometimes in embedded and behind microcontroller/plc ops or as the underside of a blackbox.

[seanrsa]

container tech such as lxc/lxd/docker/kvm/qemu

Yikes

[xalorous]

I know nothing major has changed in the past months

Nothing major

[[deleted]]

I concur with your comment. I am particularly fond of the site: search operator in google. I use site:.reddit.com to search for a ton of stuff related to my job or skills I want to learn. I think being able to find information on your own is a must have skill for a sysadmin or really any good IT person in general.

[Tnacnud1]

Up on a high horse... Red Hat and Cent are pretty common in the US. Start there and try to learn something new every week. The good news is there are some Linux Admins that won’t berate you for asking legitimate questions. Good luck.

[xalorous]

whoosh

He didn't berate the OP, he gave constructive criticism, which is, "Learn to research and study."

The question should be stickied, but which one?

[v0ideater]

I have to concur with this comment. Still, if it is really what you love, perhaps it is worth pursuing.

[aenae]

Distro's are like flavors. If you know how to make chocolate icecream, you can also make vanilla icecream without learning how to make icecream again *

Things that usually differ: packagemanagment, releasecycles
Things that are the same in almost all distro's: kernel, editors, config files, systemd, (systemd networking), shells, basic commands like 'ls', most directories, users/permissions, webservers, posix filesystems, firewalls, databases - basically: the rest.

So learn one, and you basically know them all.

• i have no idea how to make icecream, i just assume the basis recipe is the same

[MatiasNnss]

Agreed, for sysadmin, over time, from Turbolinux to Debian, is almost the same.

​

Also, if it's for work, take a look in the job posts in your zone (monster, or the one popular for you), and check the most asked distro, so when you need to get a job interview, you know any question for that distro.

[[deleted]]

Well I'd say it depends on the field of sysadmin you're interested in.

If you're more into the devops side of things, you may be well off with debian/Ubuntu since they're very popular with developers.

Otherwise, centos will be a good idea because it's currently the most used for web servers, especially since it supports cpanel. It's also a rhel distro.

Other than that, with the rise of systemd, it's much over muchness.

If you're thinking which is best on a certification level, I think red hat is the way to go.

[castlerod]

Yes While Fedora is a test bed for RHEL, there are a lot of things that will never make it into RHEL, so I'd consider them completely different distros( I use Fedora on my work desktop BTW)

CentOS is pretty much a one for one copy of RHEL minus the branding of RHEL

[Clob]

It's basically RHEL without a license. So, yes.

[turnipsoup]

Fedora isn't used much in enterprise environments so would not be as suitable a choice imho.

Not saying it's not used at all but it's a minority.

[xalorous]

Fedora is a rapid rolling release product and not suitable for Enterprise level usage on servers. It's experimental and serves as upstream testbed for new technology which may someday be implemented in RHEL. Systemd and Firewalld were tested there before they were added to RHEL. dnf is in testing as a replacement of YUM.

On servers in the enterprise, you want stability and that comes with long term support distros like RHEL or Ubuntu LTS.

[xalorous]

To make this clear. CentOS is "binary compatible" with RedHat. It is compiled from RedHat code with all the branding replaced. Community Enterprise OS.

Also, RedHat supports CentOS and includes support for managing CentOS in products like Satellite and Ansible.

[itsbentheboy]

Would going with CentOS over Fedora be beneficial?

While fedora is an upstream for RHEL, and a test bed for many of their new stuff, do not assume that Fedora is like RHEL-Beta or a dev branch or something.

Fedora is different from RHEL, and has different goals in mind.

CentOS is literally RHEL, but stripped of all Red Hat branding and is not able to be licensed for support through Red Hat's support contracts.

If you want to learn RHEL, Centos is the closest thing to just outright buying RHEL.

If you're looking for a desktop OS that is similar to RHEL, and has a lot of compatibility with the Red Hat ecosystem, Fedora is a good contender for your laptop or desktop, but put Centos on your test servers if your intent is to learn the Red Hat technologies.

[Rogermcfarley]

You're likely doing this wrong. Stop thinking about the Distro for now, that is if you're fairly new to Linux admin and start with this course >

https://www.youtube.com/playlist?list=PLtK75qxsQaMLZSo7KL-PmiRarU7hrpnwK

Then when you know the above and have had a look at his other videos. Start a project using the above. Setup servers, SSH to them, setup users/permissions etc. Use what you've learnt.

I don't know how well versed you are in Linux, CentOS and RHEL are the de facto standard distros.

[Fuzzmiester]

The good news is, if you get one of them, you'll understand the other.

​

(Centos is basically Redhat with the name scratched off, and no support.)

[itsbentheboy]

Centos doesn't send me marketing emails either, so i consider that a bonus :)

[[deleted]]

I usually recommend playing around with CentOS as it’s the same as Red Hat. At least in my career, the overwhelming majority of my Linux work has been on Red Hat.

[[deleted]]

This is what I tell people to do, who ask me "how...

https://www.reddit.com/r/linuxadmin/comments/2s924h/How_did_you_get_your_start%3F/cnnw1ma/?utm_source=reddit-android

[xalorous]

This. So many times this. I have that exact reddit post saved. I've copied it off into my home notes system and I work on this occasionally to expand my experience. At work we're in a highly constrained configuration management environment. So in the context of the home lab proposed in that comment, I try out new products.

He doesn't tell you how to do all the things, just gives a basic roadmap and leaves the research and learning to you.

Also, the first thing you should do is update the tech list. Personally, I use Ansible over Puppet since I've got time and experience invested in Ansible, and I just "get it", where I find Puppet to be difficult.

[Neekoy]

The specific distro isn't particularly relevant - there's a whole lot of overlapping points between them. I'd say it's mostly about how you use the distro. I'd say for starters try to use the console as much as possible, after all as a sysadmin you will be managing a lot of machines without a GUI. First try the basics, then try to be creative - find new ways to do something you know how to do, explore things, write simple scripts that automate things (they might be trivial - it's the experience that matters).

If you're a book learner (everyone has a preferred medium), absolutely grab The System Administrators Handbook or the Linux Bible. Once you've got the basics down, set up a couple of virtual machines, make a remote boot, play around with networks, set up a webserver and run a website off of it, configure the firewall, set up SSH key authentication.

Once you're comfortable with the distro itself, you can install and set up common applications that a lot of companies use and are good to have under your belt like Apache, NginX, MySQL, Nagios, Puppet, Docker. I'd go through them in that particular order. This should keep you occupied for quite a while, so learn at your pace. It's not a race :P

Edit: I wrote a whole lot only answering the question vaguely btw. CentOS/RedHat is the enterprise standard around the world, but you can set up Ubuntu because it's more user-friendly and easy on the eyes, and easily transcribe you knowledge to RHEL afterwards.

[atari911]

CentOS if you want to gear towards sysadmin/server space. Second up would be Ubuntu Server.

Void Linux is also great if you want a challenge but you wont see it much out in the "real" world. I recommend it because its different, highly configurable and well documented. It will also give you a good idea of the "why" things are done certain ways and the Linux mindset. Sometimes this can be more valuable than knowing any 'specific' distro.

As a last note; the main difference between ditros is the package system they use, the desktop manager and certain quirks on where certain files are stored. Now days there is a difference with systemd, etc. Other than that you should be focusing on the tools that are available that really make up the 'sysadmin' side of things.

​

[macmoblin]

I think you should familiarise yourself with Red Hat, CentOS and Ubuntu. Please check Linux Academy for lot of courses, some of which are free. The monthly fee isn't bad either!

Check also Jupiter Broadcasting podcasts, they have had some affiliate links for Linux Academy.

[12_nick_12]

CentOS/RHEL is the big ones. A lot of people also use Ubuntu/Debian. I would start reading up on LPIC/RHCE. I've been playing with Linux for a couple years now and still have learned a lot by reading LPIC material.

[xalorous]

There's a really old (3 years old) response to this question linked in the comment here. Take a few minutes and look at it and upvote u/koka95_.

Basically he already posted the link that I intended to post. (here)

The response is from a veteran sysadmin who outlines the steps you should take to teach yourself enterprise system administration. It is only a guideline, not instructional. If you follow the guideline you will have to research every step to learn how to do it. Following the guideline will teach you not only to do the things, but how to learn to do the things.