RHEL5 installation Guides

RHEL5 (Redhat Enterprise Linux 5)requires a few more semi-expert steps not usually expected from production linux distros. Please feel free to amend these if you can help others avoid frustration and loss of time.

1. Check that your LAN adaptors are enabled in BIOS. They aren't necessarily on by default. Connect a live cable. Intel platforms tend to flash the screens telling how to access BIOS menu very briefly, at an unrelated moment. It's usually

[F2]

or the

[Delete]

key.

2. Best start with on-board video adaptor, if present, by removing any add-in video card.

3. For Red Hat 5, installation numbers determine whether virtualization (Xen kernel) or non-virtual kernel is installed by default. It's OK to install virtualization, but then you will likely need to add non-virtual kernel later. Virtual kernel is not supported by as many plug-in video cards.

4. Unlike EL4, several needed optional

.rpm

's aren't shown in the software install menus.

yum-install

, if it works for you, may be the most convenient for adding them after initial installation. (Be sure to change your view from

[All installed]

to

[All available]

packages, with the distribution DVD in the drive so it can be searched.) Otherwise, you have to search the DVD manually and use

rpm

on the command line

5. If you installed the xenkernel, add the other "regular" kernel. The grub menu should have been set up automatically to allow selection. You may wish to edit

/boot/grub/grub.conf

to switch the default to the non-virtual kernel, which is preferred when the xenkernel isn't required. In either case, add the kernel development installation for the kernel you will be using.

6. Newer Intel platforms - like SDPs - usually require building a network driver to enable the LAN - for example, the newest

e1000

driver, or the

igb

driver for the latest chipset's NICs. Source code may be provided on a CD, or you may need to download from

http://sourceforge.net

and burn one. Unpack it to your build directory, and

cd

to the

.../src/

directory. Kernel-source rpm must be installed by adding kernel development option. e1000

Makefile

has a built-in search path for kernel source, which probably doesn't include the location of EL5 kernel source. Find it and edit it into

Makefile

. Then, su

7. Certain software installations (e.g. Intel Cluster tools components) require you to first run

ssh

from the command line, logging into the connection you have just set up, and any other machines in your machine connections file. It isn't enough that you may have used your new connection to download the install package.

8. Intel compilers (thenselves) require both 1.) the gcc development installation and 2.) the added installation of the libcompat for i386 (32-bit) C++ for which rpm is present on the DVD. Failing to install these will produce an unexplained abrupt install failure because the compiler itself didn't run right. If you have missing dependencies in Intel software install, they should be described in an install.log, or can be found by trying the lower level rpm installs individually from the command line.

9. Add-in video cards require downloading a driver installer from the manufacturer's web site. Check carefully the downloaded software exactly matches the video card being used.

10. EL5 is supposed to institute information in /proc/ sufficient to determine the assignment of OS core IDs to CPU and cache. This sppears not to be implemented in early kernels. Under EL4, Intel OpenMP programs supported choice of affinity with KMP_AFFINITY environment variable, which appears non-functional in EL5. In order to get similar results in EL5, set the verbose flag in EL4, e.g. KMP_AFFINITY=compact,verbose, which will give the OS core ID sequence, then use that sequence with taskset in EL5, e.g.

Yum automated software installation and update for Red Hat Linux

Yum is the easiest way to keep all programs up to date. It downloads and installs the latest version of a program. A single command can update all software installed, including third-party software, security updates and operating system. It can do the updating automatically in the night. In this howto, we install yum and make it do all the above.

Yum is similar to, but better than apt, apt4rpm, windows update, up2date, yast and many other package managers I have seen.

Yum works in a safe, standardized way. It uses rpm (Red Hat package manager) for installing programs. Authenticity of packages is checked with strong gpg encryption. Package repositories are just folders on a web server.

This tutorial is for Red Hat 9. If you are using the newer Fedora Core 1 or later, you already have yum installed. For configuring Fedora version, see unofficial Fedora Faq.

We will install yum, then choose trusted packagers and start installing programs. We will also see some yum tips.

(c) Install yum

Red Hat has rpm package manager installed by default. We use rpm to install yum.

Download yum-2.0.3-0.fdr.1.rh90.noarch.rpm

Open command prompt: Main menu (the red hat menu on bottom left corner), System Tools, Terminal. Become root with

su -

. Notice how your prompt turns from

$

to

#

.

Go to the folder where you downloaded yum. Most likely

cd /home/your-user-name/

. If you can see the file with

ls

, you are on the right place.

rpm -Uvh yum*.noarch.rpm 

In the command above,

rpm -Uvh

means installing just like

rpm -i

you may have used allready.

-Uvh

just displays some extra info and erases old version of program if necessary. You can

rpm -q yum

to see if yum is installed. It should tell you the version number of yum.

# rpm -q yum yum-2.0.3-0.fdr.1.rh90 

Add trusted packagers to your keyring

In yum, it really does not matter if enemy takes over the internet and fakes to be some website offering software. All software is cryptographically checked before installation (if you have set

gpgcheck=1

in yum.conf). To install some software, we must tell yum who we trust.

rpm --import /usr/share/doc/yum-*/Fedora-GPG-KEY

rpm --import /usr/share/doc/yum-*/RPM-GPG-KEY

We installed the key of Red Hat Inc, as we obviously trust the company that compiled our operating system. We installed Fedora's key, as we have allready installed yum packaged by Fedora. These two keys are probably the most usefull ones.

Start installing software

yum install lynx

Because it is your first run, it first downloads headers that contain information about what is available. This can take as long as 20 minutes, but it only needs to be done once. Yum prints the names of headers it downloads

Gathering header information file(s) from server(s) Server: Fedora Linux / stable for Red Hat Linux 9 (i386) Server: Fedora Linux / testing for Red Hat Linux 9 (i386) Server: Red Hat Linux 9 (i386) Server: Red Hat Linux 9 (i386) updates Finding updated packages Downloading needed headers getting /var/cache/yum/fedora-stable/headers/leafnode-0-1.9.43-0.fdr.1.rh90.i386.hdr getting /var/cache/yum/fedora-stable/headers/libzvt-devel-0-2.0.1-0.fdr.5.rh90.i386.hdr getting /var/cache/yum/fedora-stable/headers/mhash-devel-0-0.8.18-0.fdr.1.rh90.i386.hdr    [..] Resolving dependencies Dependencies resolved I will do the following: [install: lynx 0-2.8.5-7.1.i386] Is this ok [y/N]: y 

Accept with

y

and press enter. Yum downloads requested packages and installs them.

If any additional programs, dependencies, are needed, yum will ask if you want to install those too. For example, lynx needs perl-CGI, so if we don't have that installed yet, yum installs it.

Calculating available disk space - this could take a bit lynx 100 % done 1/1  Installed:  lynx 0-2.8.5-7.1.i386 Transaction(s) Complete 

Now all users can use lynx right away. No reboots, no changing cdroms, no nuisance. If you are still root (have a

#

on your command prompt),

exit

.

Now try

lynx

. If you can run lynx (the text mode web browser), you have succeeded. Congratulations, you have now installed the state of the art package manager yum.

Yum tips

That was just too easy, wasn't it? To have some fun with yum, try

yum list "*ssh*"	# lists packages that have "ssh" in the name chkconfig yum on        # make yum update all programs every night yum remove up2date      # remove a program, dependencies handled yum -y install curl     # -y answers "yes" to all questions 

Links

Duke University 2003: Yellow dog Updater, Modified. Official homepage of yum. Has a list of yum repositories.

Fedora Project 2003: Fedora.us. The biggest yum repository, now merging with Red Hat.

Saou, Mathias 2003: Freshrpms.net. The first big automated software repository for Red Hat. Best packages of many programs, such as mplayer and sylpheed. Good documentation.

To use yum in some real application, try some of my other tutorials. Most of them use yum to install software.