What are some essential linux cmds an admin show know? I have a interview soon

[Arkitech]

I had 2 phone interviews for an admin position that will require some light linux work. I'm scheduled for a 3rd in person interview this coming Friday. I've had some experience in a little bit of Unix admin work about 4-5 years ago, but it was mostly maintaining scripts. Then I've played around a bit with a few linux distros.

I would like to bone up a bit more on linux commands. I don't plan on overselling what I'm capable of, but all the same I'd like to be prepared. Any links or advice would be appreciated. Also I'll probably hunt down a light distro to play with in VMware for a bit.

 

[lxskllr]

http://ubuntuone.com/7Jrqn87sZJTt8itehl9VWM

Edit:
http://ubuntuone.com/2HXg7vnSou6rPZFKlgdfP5

 

[Arkitech]

http://ubuntuone.com/7Jrqn87sZJTt8itehl9VWM

Edit:
http://ubuntuone.com/2HXg7vnSou6rPZFKlgdfP5

Thx man, very helpful. Bookmarking both of those links.

 

[sourceninja]

To me most linux admin work isn't commands as much as how to configure applications and where to find important configuration files.

Like knowing where to find the IP settings for an port on both redhat and debian.

 

[mv2devnull]

Like knowing where to find the IP settings for an port on both redhat and debian.

A useful example. The format and location of configuration.

However, in some distros the assumption is that you do not edit those files directly, and use a configuration tool instead. Tool is a command. On one hand an attempt to ensure consistency of the configuration and on another a chance to have an UI that could present the valid options to the user.

There can be more than one tool for one job (e.g. for maintaining a LDAP database). There can be multiple, mutually exclusive systems in same distro.


Bottomline is (excluding ubiquitous dd if=/dev/zero of=) that the distros are different, and thus "general admin commands" is a stranger. Or maybe not. Knowing only one system decently, I can get around in foreign systems. Eventually. Without paying attention to the wake of havoc on my tail ...

 

[PrototypeZ]

To me most linux admin work isn't commands as much as how to configure applications and where to find important configuration files.

Like knowing where to find the IP settings for an port on both redhat and debian.

Agreed with the above to a certain extent, specifically with regards to what files and where. If you know the general commands for most things that is great because the rest is just a man away from the syntax needed to perform the task.

As a hiring manager, understanding fundamentals is important along with proven knowledge. If a candidate doesn't know something, we would rather have them tell us versus guessing and giving a long winded BS explanation. Don't lie on the resume because it will bite you in the ass.

Also be sure to sell soft skills and any sort of project experience. If somebody is tight on soft skills and intelligent with some technical knowledge, we can sometimes take a chance and pass them through a round of interviews to give them benefit of the doubt.

If you want to see some questions that I ask on a routine technical interview, shoot me a PM.

 

[nephilim2k]

Learn unix commands. Like how to vi a file, or find out how much space there is on an area in human formatting etc. This is then transferrable to almost all linux builds as well as apple builds.

 

[unokitty]

I had 2 phone interviews for an admin position that will require some light linux work. I'm scheduled for a 3rd in person interview this coming Friday. I've had some experience in a little bit of Unix admin work about 4-5 years ago, but it was mostly maintaining scripts. Then I've played around a bit with a few linux distros.

I would like to bone up a bit more on linux commands. I don't plan on overselling what I'm capable of, but all the same I'd like to be prepared. Any links or advice would be appreciated. Also I'll probably hunt down a light distro to play with in VMware for a bit.

Depending on your background, you might find it useful to visit Eli the Computer Guy's Linux video tutorials.

Best of luck,

Uno

 

[Randybob01]

Grep, cut, find. And for loops. Those make my day significantly more productive.

http://linux.die.net/

^ Awesome. Just type any command into the search box, and you are blessed with a man page.

 

[JD50]

Learn some Python. If you don't know how to script, you're not a good Linux Admin, IMO.

 

[JD50]

Learn unix commands. Like how to vi a file, or find out how much space there is on an area in human formatting etc. This is then transferrable to almost all linux builds as well as apple builds.

If you're looking at a Linux position, there's really no point in learning Unix commands, then trying to translate that into Linux commands. Just learn the Linux commands.

More than likely you'll be on a RHEL system, so download CentOS and take it from there.

 

[mv2devnull]

@JD50: What are you talking about?

1. Scripting is good to know. Shell scripting gets you a long way, although Perl and Python can get an extra mile.

2. A lot of "Unix commands" are GNU commands, and GNU/Linux has then just the same. That set of commands is the Swiss army knife that works everywhere and for anything. Specialized distro-specific configuration tools are important, but specific.

Give an example of "Unix command" that does not exists in Linux.

 

[sourceninja]

Try to use tar on red hat the same way you do on Solaris. The options are all different.

 

[mv2devnull]

From 'info tar' on CentOS 6:

There are three styles for writing operations and options to the command
line invoking `tar'. The different styles were developed at different
times during the history of `tar'.

Old options are kept for compatibility with old versions of `tar'.

As far as we know, all `tar' programs, GNU and non-GNU, support old
options. GNU `tar' supports them not only for historical reasons, but
also because many people are used to them. For compatibility with Unix
`tar', the first argument is always treated as containing command and
option letters even if it doesn't start with `-'.

tar in Solaris might have a yet different style, but isn't the main point to know that there is a tool 'tar' that performs function X on most platforms?

 

[JD50]

@JD50: What are you talking about?

1. Scripting is good to know. Shell scripting gets you a long way, although Perl and Python can get an extra mile.

2. A lot of "Unix commands" are GNU commands, and GNU/Linux has then just the same. That set of commands is the Swiss army knife that works everywhere and for anything. Specialized distro-specific configuration tools are important, but specific.

Give an example of "Unix command" that does not exists in Linux.

Some commands are not the same, so why wouldn't you want to learn the commands on the platform that you will actually be working on?

 

[JD50]

From 'info tar' on CentOS 6:

tar in Solaris might have a yet different style, but isn't the main point to know that there is a tool 'tar' that performs function X on most platforms?

Option 1. Learn tar on Solaris, then learn the differences in RHEL since that's what you'll actually be using.

Option 2. Learn tar on RHEL.

I pick option 2.

 

[bobross419]

Knowing what a command does (tar creates archives) and where to find info (man tar) is going to be more important for "light linux work". There is no point in investing the time into learning the nuances of a command based on an assumption of what systems you will be dealing with. For minor admin tasks, a broad view is going to be a whole lot more beneficial than a deep view.