This is my very first post regarding Linux on any forum. Because this is first time ever I am trying to learn Linux in 14 years. I have installed CentOS 6 as guest OS using VMware on Windows 7 system.

I have successfully installed Apache, MySQL, PHP, phpMyAdmin and ffmpeg using Google search. When I was searching about how to install these softwares I found that Linux seems to be very complex platform compared with Windows because nothing installs as simple 'next' clicks on Linux.

I really scratched my head while installing ffmpeg because it threw lot of errors and here I am listing them though I have successfully installed it but I want to learn about those commands.

First after fresh install of CentOS when I used the command

yum install ffmpeg

it threw no package found error. And same error appeared when I tried to install phpmyadmin

yum install phpmyadmin

After searching quite a bit I found that where CentOS looks by default about the packages, there seems to be ffmpeg and phpmyadmin missing.

Then I used couple of commands and edited a file too

i) Inserted following lines to /etc/yum.repos.d/dag.repo
[dag]
name=Dag RPM Repository for Red Hat Enterprise Linux
baseurl=http://apt.sw.be/redhat/el$releasever/en/$basearch/dag
gpgcheck=1
enabled=1

ii)rpm -Uvh http://download.fedora.redhat.com/pu...6-5.noarch.rpm

iii) rpm --import http://apt.sw.be/RPM-GPG-KEY.dag.txt

iv) yum repolist
v) yum update
vi) yum install yum-priorities


After above six steps when I tried
yum install phpmyadmin (it was a success)

and yum install ffmpeg also installed ffmpeg BUT an older version.

Now, I am here to seek help about above six commands though I guess it actually updated the CentOS about new available softwares but what each command exactly do?

And one more thing that is ffmpeg is installed but its 0.6.1 ver while I want the latest release. Here are few questions

1) Why CentOS didn't pick the latest release itself?
2) Now what changed I need to do to make CentOS install latest release of the software when I issue command "yum install"?

And thank everybody for your precious time.

You really don't sound like you need much help.

You kind of have a lot going on here.

Distro's are kind of "use" created. Centos is a clone of red hat and not really a good choice for multimedia. One of the reasons you pick a distro is to provide some sort of uniformity to the OS. A distro that is geared to be on the leading edge of multimedia would have people and repositories and a software management that provides that feature.

So the issue kind of gets to this. Do you want a stock fully supported distro or do you want to go out on a limb and break the package management or do you want to get a distro that suits this need for latest packages?

While I've not used a Red Hat-based distro much (I'm more familiar with Debian), I can answer a few of your questions:

1) Why CentOS didn't pick the latest release itself?

This is because you are installing the package (ffmpeg in this case) from the CentOS repositories. Most distributions have what's called a Software Repository, which has different programs that the makers of that distro decide are useful to have pre-compiled (ready-to-install) for your distro. If you download ffmpeg from their website, you will get the most up-to-date version of the program, because it's coming direct from the maker, but they may not have a handy package (.rpm file) for your distribution, so you would have to compile it from source-code.

Because you're relying on the repo and not the official website of the program, it might not be the latest version depending on the priorities of the package maintainers (the people that compile the source of the program into that handy package that only requires one command to install).

Even though you might not get the latest version of a program, there are some major advantages to using the Software Repos:
- When installing, any other programs that ffmpeg or other needs are installed along with it. These other needed programs are called dependencies.
- The package might be customized by your distro with certain options that fit it better. Example: I installed squid on my Ubuntu server from the repos, and the package maintainers had disabled a feature in squid that Ubuntu already provided (logfile_rotation if you were wondering).
- Updates for all your packages are handled with one command

As far as the commands you used to do this:
i) You added the location and various options for a repository in the yum package sources list
ii) You upgraded the specified package
iii) You imported the GPG key for that repo. These keys are so that you can tell whether or not you are talking to the real repo and not a fake one.
iv) Not sure on this one, but I think it loads the changes you just made on the repo list
v) This updates your list of packages and versions so you can see what is available to download and install
vi) not sure on this one either except that it's installing updates

Sorry that's so long, but I hope it answered most of your questions.

Hi Peon1,

Welcome to the Linux world. I have been dabbling with Linux for 14 years and am still learning so do not get discouraged Well perhaps not 14 years but it seems like it.

As to CentOS and multimedia... First off have a look at centos.org. There is a good overview of installing software at https://www.centos.org/modules/newbb...28724&forum=54

I have been playing with CentOS as a possible replacement for Ubuntu which I am currently running (for a couple of reasons). The main sticking point was the inability to install vlc media player and recoll full text search tool. I was able to build the recoll package (rpm) myself and install it on CentOS 6. vlc was another learning experience (still in progress).

CentOS is derived from Red Hat Enterprise Linux. RHEL is more "server" oriented so the available packages in the RHEL and thus CentOS repositories is thus somewhat limited and sometimes behind the times. An example is Firefox which is still at 3.6.x. If you manually install a newer version of Firefox you risk conflicting with some of the support libraries needed by CentOS or other programs. And you thought that dll hell was a Micro$oft invention

There are other repositories available for RHEL and CentOS. For example:

EPEL (Extra packages for enterprise linux) which are derived from the Fedora project
RPMForge (or dag - I think they are the same or at least related)
ATrpms (related I think to Scientific Linux - another off shoot of RHEL)

I have used ATrpms to install vlc media player. However, some of the support libraries conflict with those in RPMForge and EPEL. I have an open thread on the CentOS forum about the issue https://www.centos.org/modules/newbb...33907&forum=56 It is sort like trying to juggle cats

That said, there is another side to the coin. Some distros such as Ubuntu, Mint and others tend to include everything including the kitchen sink and a '59 Edsel in their repositories. This mitigates the conflicting pieces and parts situation and packages will be as up to date as the repo maintainers choose to keep them.

Stepping back a little and to answer one of your first questions... When the author of a program creates a version upgrade they may make it available on their web site or on SourceForge or another resource. The new version must be packaged for the specific distributions and placed in the repositories for the distributions. This extra stem helps to make sure that the package will install properly in the distribution and hopefully will not break something else. This takes time and thus the distro versions will lag the programmers' versions.

As you are running VMWare have a look at some other distros. If you try Ubuntu I would recommend the 10.04 Long Term Support release. The latest release, 11.10, has the Unity interface which looks like a smart phone or tablet computer.

Ken

You are welcome to LINUX.

Then where can I find info about the specialty of all distros and moreover what should I do if I need a mix of two distros?

I think best fit is to go on a limb and break the package management because as I asked above what if I am looking for Linux distro with good multimedia support and web server to perform good on high load.

Best thing I like about Linux is that it introduces you lot of good and open-hearted people.

And thanks for tipping me to install Ubuntu, I was also thinking about it but I'll take care of the version you recommended.

Thanks again.

Distrowatch.com may be one place to see some basic info.

I don't recommend a beginner to break the package feature of the distro. You can if possible. Usually the application you want has some issue and that is the reason it isn't provided.

The problem with linux apps is there is some much dependency. For a very simple example. Say you want to install some new latest app version. It needs say (fictitious) libdoda4.8. Now that distro has also been linked to 12 other apps with libdoda4.4. and they did a bad job and it doesn't follow more than libdoda. Now what do you do? Do you wait for upstream to fix all libdoda apps or an app that automatically monitors libdoda versions?

You can break dependency if you want and it can easily work too.

Generally it is not a simple as waiting for someone to take the new app source and compile it on your system/version.

I think that you are taking an excellent approach by installing Linux into a virtual machine.

Welcome to Linux. As one who has trod the same path as you ... "enjoy the ride."

Persevere, with patience, and your patience will be rewarded.

He was installing Apache though, and CentOS is a good choice for a web server.

I have couple of questions to ask.

i) In windows new software is installed in Program Files, where its stored in Linux?
ii) How software can be completely uninstalled if something goes wrong? (I mean returning back to previous state)
iii) How can I look into source code of CentOS 6 because I am also interested to get my hands dirty with C code?
iv) How I can look into 'Root' folder using GNOME?

And I'll be grateful to you if you can help resolving these problems.

In my very short experience with Linux, I have found that its help is not readily available online. I mean 'exact' help as you can get for Windows because when I search for particular problem then lot of solutions come up in forums/blogs but when I try them I get more errors while people on those forums/blogs seem to have resolved their issues. But when I search for new errors then it seems only few people match with the chain of my errors. And then I am finally able to solve my problem.

And I think it is because of lot of variations in Linux builds and different configuration of different people on different machines.

I am not discouraged at all with complex issues with Linux. I am getting more interested.

Could you please guide me step by step things/problems I should resolve to become a good admin?

I think there must be some way to find out dependency of a software and then figure out other dependents and then it can be figured out that which software is more important to be in working (latest) state.

i) /usr
ii) man yum
iii) http://vault.centos.org/5.7/os/SRPMS/
iv) nautilus /

You're already on your way to being a good admin. This is how I learned as well, by trial and error. It takes a while to train yourself to think outside the Windows environment, but once you know how, you find it easier to work from the command line than a windowed environment for most things.

Some good resources are http://www.brennan.id.au/01-Introduction.html - That site goes over how to install and configure several different popular servers. It also uses fedora, which means the instructions should work well for CentOS as well.

Depending on how good you are at using the command line, this might be of help as well: http://linuxcommand.org/

Another good way I found to practice is to write your own scripts for doing things on the server. This way, you can learn a lot of the more obscure things about the bash shell (like > or < and | ) that end up saving you a bunch of time.

The documentation on the program's site should have a list of dependencies. There's also a way to use yum to list (not download or install) the dependencies (among other things) for that program, though they might be different between different versions of the program.