Keeping Your System Up-to-date

Bill Moss
July 2001

Introduction

Why should you set aside a few minutes each week to keep your system up-to-date? The primary reason is that an up-to-date system is more secure than a system with old software. If your system is compromised, it may be used to compromise other systems on campus, so keeping your system up-to-date is part of being a good network citizen. The speed with which problems are found and fixed in Linux is really fast. Red Hat has taken most of the pain out of the process of keeping your system up-to-date. First, you register with the Red Hat Network (RHN) and set up a hardware and software profile of your machine. Each time you login to the RHN, you will be informed of the available updates that match your machine profile. You can then download the updates and apply them in a few minutes.

Registering your machine with the Red Hat Network (RHN)

There is no charge to become a registered user of RHN or to create a system profile. Visit the RHN main page at www.redhat.com/network to get started. Your RHN account lets you review user preferences and your system profile. To enable other services, you need to purchase a subscription. With a subscription you get the "Software Manager" which automates the process of downloading and installing updates. If you don't mind doing a little work yourself, you can do the same thing without a subscription. You can ftp the required updates to your machine and install them in a matter of minutes.

You can register with RHN at www.redhat.com/network or you can use the RHN registration application that comes with Red Hat 7.1:

GNOME Menu: Programs -> Start -> System -> Red Hat Network

The registration process will place a digital certificate on your machine (/etc/sysconfig/rhn/systemid). If set up your account via the web, you will have to issue the command "up2date" as root in a terminal window to create your initial system profile. This is done automatically when you use the RHN registration application.

Updating your system packages

• Logon to the RHN.
• Hit the "View ALL" errata button.
• For each listed update, click on the Errata Report link, then on the Expanded Errata Report link, and note all the update RPM files listed for your version of Red Hat. We'll assume that you are using version 7.1.
• Do an anonymous ftp to updates.redhat.com and CD to "7.1/en/os/i386" and download the RPM files that you noted in the previous step. If you are using GNOME, you will find it convenient to setup the FTP application gftp for this purpose.
• In a terminal window as root CD to your RPM download directory and issue the command "rpm --checksig *.rpm". This will check to make sure these rpm's have not been tampered with. Next issue the command "rpm -Fvh *.rpm". When the updates are done, issue the command "up2date". The "up2date" command will update your system profile on the RHN.

Updating your kernel

If you find an Errata Report title that begins with "Kernel", then Red Hat is recommending to you that you upgrade your kernel. A kernel update is a little more involved than package upgrades, but not much. Red Hat has a How-To document on kernel upgrades that will take you through it step-by-step. After you have done it once, then next time will be a piece of cake. The URL for the How-To is

http://www.redhat.com/support/docs/howto/kernel-upgrade/kernel-upgrade.html

In the last step of the kernel upgrade How-To, you are told to use the command "/sbin/lilo" to update the lilo boot loader. Don't do it yet. If you have followed the How-To instructions, you now have two kernels you can boot. In "/etc/lilo.conf", the new kernel is labeled "linux" and the old kernel is labeled "linux.old". If you are using the Windows 2000 boot loader as explained in Dual Booting the Clemson Dell Latitude C600 ..., now is a good time to undo something you did when you set up dual boot. In "/etc/lilo.conf" after the line containing "install=/boot/boot.b", add a line containing "prompt" followed by a line containing "timeout=50". Now can issue the "/sbin/lilo" command, followed by the commands "dd if=/dev/hda2 of=/tmp/LiloBoot.bin bs=512 count=1" and "mcopy /tmp/LiloBoot.bin /mnt/windowsc". Reboot. The Windows 2000 loader will give you a choice of "Windows 2000" or "Red Hat Linux 7.1". After choosing the "Red Hat Linux 7.1", you will see the lilo prompt for 5 seconds before the default kernel with label "linux" is loaded. If this kernel fails to load, you have options. You can boot from the "emergency boot disk" that you made while following the Dual Booting the Clemson Dell Latitude C600 ... instructions, or at the lilo prompt you can type "linux.old" to boot from your old kernel. This way you can go back and start over if necessary.

Upgrades for the 7.1 distribution (as of July 22, 2001)

If you set up your C600 for dual boot and then follow the above process for setting up a RHN account and system profile, you will find that about 20 updates are available for the 7.1 distribution. One of these is a kernel upgrade from 2.4.2-2 to 2.4.3-12.

Upgrades for the 7.1 distribution (as of October 29, 2001)

In the last few weeks a number of updates for 7.1 have become available including a kernel upgrade to 2.4.9-6.