Introduction

When the Linux kernel boots, it assigns names (eth0 etc..) to network devices in the order that it finds them. This means that two different versions of the kernel, say 2.4 and 2.6, might find the network interfaces in a diffent order. When this happens you might have to swap all the cables to get your connections to work the way you want. The proper way to do this is to name the interfaces with the nameif command (part of the net-tools).

You can install net-tools by running:

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Overview

In addition to the basic requirements of DHCP, TFTP, and NFS, you will need to add another component called PXE (Pre-boot Execution Environment). Much like Sun systems use the OpenBoot firmware to allow booting from their network devices, PXE works with your x86 system to provide that same functionality. This means that before you begin, be sure your client is PXE aware. If you have older hardware, you may want to look into Etherboot as an alternative. To enable PXE on your client, simply enter your systems BIOS and turn it on.

With PXE enabled and listed as your primary boot device, your system is ready to boot from the network. Once the request is received by DHCP from your client, the server assigns an IP address and tells PXE where to find its pxelinux.0 file. This binary is then transferred through TFTP with instructions on the location of the netboot image. This file contains the data stating which kernel and initial ramdisk to load. It also gives the necessary information to NFS to mount the install directory. After all of the above is accounted for, your system will begin installing in the same manner as if you installed it from CD-ROM.

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MySQL replication allows you to have an exact copy of a database from a master server on another server (slave), and all updates to the database on the master server are immediately replicated to the database on the slave server so that both databases are in sync. This is not a backup policy because an accidentally issued DELETE command will also be carried out on the slave; but replication can help protect against hardware failures though.

Configure The Master

First we have to edit /etc/mysql/my.cnf. We have to enable networking for MySQL, and MySQL should listen on all IP addresses, therefore we comment out these lines (if existant):

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MySQL replication allows you to have an exact copy of a database from a master server on another server (slave), and all updates to the database on the master server are immediately replicated to the database on the slave server so that both databases are in sync. This is not a backup policy because an accidentally issued DELETE command will also be carried out on the slave; but replication can help protect against hardware failures though.

Configure The Master

First we have to edit /etc/mysql/my.cnf. We have to enable networking for MySQL, and MySQL should listen on all IP addresses, therefore we comment out these lines (if existant):

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Setting up a Certificate Authority

On a separate server, preferably isolated from the network and physically secured, create the Certificate Authority that will generate all the certificates for TLS encryption:

[root@host]# yum install openssl openssl-devel
[root@host]# vi /etc/pki/tls/openssl.cnf
[root@host]# cd /etc/pki/tls/misc
[root@host]# ./CA -newca

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1. Maybe you do not need the full kernel source

If you need to compile a kernel driver module, the chances are you do not really need the full kernel source tree. You might just need the kernel-devel package. (If, however, you are certain that the full source tree is required, please follow the instructions in Section 2.)

In CentOS-5, there are three kernel-devel packages available:

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