Linux/Unix FAQ

[mikek147]

Hi everyone. We're going to try something new in this forum. This particular thread is going to become a sticky thread so it remain on top, and will contain frequently asked questions with their answers on everything to do with Linux and UNIX. Each post within this thread will contain one question/answer pair. And hopefully, any and everyone may contribute.

There will be some rules. This is to be used for just question and answer pairs. That means no general comments, rants etc. All comments should be in the posters own words. If quoting from some other source, please list the source of the quote. And please, re-read what you write, before posting, to insure that others not as knowledgeable as yourself can understand what is written.

Hopefully, over time, this thread can become an important source of information for 'nix user. -mk

[rami3]

The age old question (well a couple of years old anyway) that seems to be asked a lot, the answer is quite simple – whichever suits your needs, that’s the beauty of Linux you actually have control of the product you put onto your system.

Each distro has its advocates, some people will tell you to use Slackware or Debian because that’s the real Linux, and others will tell you to use Redhat or Mandrake because of ease of install, I’m just going to tell you a little bit about the distro’s I know and have personally experienced and let you make up your own mind.

Debian GNU Linux

This is an excellent distro, though not for the complete Linux newbie, aimed more at intermediate to expert users, who aren’t afraid to get their hands dirty under the hood and do a little manual configuration, the latest version called Woody is the third release from Debian. I won’t lie and tell you the installation process is easy, the version I use is Potato 2.6 so I can’t comment on Woody, but basically its text menu driven installation with a lot of Linux talk in it, no fancy GUI’s or wizards, there are explanations to what you’re actually doing when you go through the menus, but if you’re a newbie to Linux I would advise trying another distro to start you off. Debian is completely free, they don’t try and sell you a thing, their philosophy is to make a better product that serves the end user as best it can, not to make money, and this I feel is the reason why a lot of users choose to use it, even newbie’s.

SuSE / Mandrake / Redhat

The 3 biggies, very easy to install (some would argue as easy as a Windows 98 install), aimed at the mass market, and they aren’t going to sell too much if you can’t get it on your system. The install process is a simple point and click affair with all 3, very simple, all can be bought as boxed sets, with every possible application you could ever need included, the documentation that comes with SuSE and Redhat is second to none, I downloaded Mandrake so I can’t comment on the documentation included with it, but all 3 would be the perfect choice for a newbie to get their hands dirty with Linux, the more experienced would also find them useful, because like I said every tool, application and library you will need is included.

Conectiva

This is another very easy Linux install, IMO the easiest I have ever done, I got version 8 off a magazine as 2 large ISO files so I can’t comment on documentation, boxed sets or any of that, the install is again point and click GUI driven, aimed at the mass market and another excellent choice for a newbie.

Peanut Linux

The version I used was 9.2, the install was much like Debian’s install, could be confusing for a newbie to get through.

Slackware

Definitely not one for the complete newbie, don’t get me wrong it’s an excellent distro, but installing can be hard going, as can getting some hardware to work, your going to have to get your hands dirty if you try Slackware. The install process is done via a text driven menu system much like Debian or Peanut, but selection of software is easier IMO as you can choose to interactively select what you want on your system. Each section comes up separately during the installation, and you select the software you want, system dependant packages are already selected, if you inadvertently deselect one you will be warned. I should add that all distro’s will warn you of this.

When selecting which distribution of Linux you’re going to use just remember that Linux is free, if you don’t like one for whatever reason get your hands on another, my advice for what’s it’s worth would be to use what your comfortable with, I’ve only wrote about 7 here there are loads more out there to choose from and a lifetimes reading on the internet to help you decide.

SuSE
Redhat
Mandrake
Debian
Conectiva
Slackware
Peanut Linux

Distro Watch

RB

[rami3]

It doesn’t, to demonstrate first open up a shell, now issue issue the free command you will get something back like:

	  total   used     free   shared   buffers  cached
mem:      127888  119944   7944   52860    21788    21048
-/+ buffers/cache:77108    50780
swap:     132040  540      131536

At first glance you will see under free that there is only 7944k of memory free, this would suggest that there is only 7944k available to the system, you would then think your OS hasn’t enough memory available to run anything, don’t worry its just an illusion, to help you understand I’m going to quickly explain how memory is managed within Linux.

Virtual Memory and Swap Space

Each process needs its own area of memory called core memory as a place to run the code and store variables etc, this memory is allocated to that process but not actually used, when a process starts it is allocated memory when a process is running it uses memory simple as that, if a process needs memory and there seems to be none free it takes it from a sleeping process, e.g. a process that is not currently active or being used.

Programs like the X Server use a lot of memory to get around this Linux uses a strategy called Virtual Memory, it does not try to hold all the code and data for a process in core memory, instead it keeps in core memory only a small working set of instructions for the process, usually the base instructions essential to the running of that particular process, the rest of the process's state or instructions are left in a special area on your HD called Swap Space, as the process runs Linux tries to anticipate how the working set will change and keeps only the pieces that are needed in the core memory.

Top

If you run the command top you will be presented with a list of the currently running processes and their attributes, look at the memory usage for each process, definitely not all of the memory is being used, a process called X will probably be the biggest hog, along the top of top (no pun intended) you can see the state of the processes running on your system, how many are sleeping, running, CPU state, memory usage etc, all very valuable information on the state of your system.

Free is a good command to run for a quick glance of your system memory’s state, some switches you can use are –m (display in megabytes), –k (display in kilobytes, the default BTW), -b (display in bytes), but the next time your worried about memory usage on your Linux box run the top command to appease your fears.

RB

[llama]

VI is a great command line editor, once you get the hang of the commands. Here's a cheat sheet that has helped me a lot.

http://www.lagmonster.org/docs/vi.html

[dannilydoodily]

I've been meaning to post these for a while to give some FreeBSD resources:

Official FreeBSD Links:

The FreeBSD Handbook

The FreeBSD FAQ

Online Man Pages

Search FreeBSD Resources (including mailing list archives)

*BSD via Google

Unofficial but helpful links to HowTos and other resources:

Daemon News

FreeBSD HowTos

FreeBSD Diary

Greasy Daemon


Some are pretty well-known but hopefully it will help if anybody is searching for *bsd-specific stuff.

[rami3]

Have a look at,

Linux BASH Commands

[tironsi]

UNIX Reference Desk: http://www.geek-girl.com/unix.html is a general information site about UNIX that I have found helpful. Many links are dead and the page needs to be updated, but it still has tons of useful working links.

P.S. I don't see too many question/answer pairs so I decided to post a link too. I hope it's OK.

[mikek147]

Linux Primer

[hongman]

A place to download Linux ISO's:

LinuxISO.org

**NB**

When you burn the ISO, check afterwards that there is more than one file on the CD/DVD. If there is only one file xxx.iso then you have burnt it incorrectly.

[Train]

Linux Live CD list
http://livecdlist.com/

My favorite
http://sourceforge.net/projects/anti...inal/MX-krete/

Main Page
http://antix.mepis.org/index.php?title=Main_Page