XenSource RPM Installation Notes

Introduction

XenSource is providing RPMs to enable customers and partners to quickly and easily realize the benefits of running their systems under the Xen hypervisor.

Note that these RPM sets are a BETA test release. They support installing Xen for 32-bit SMP architectures only.

RPMs are available for the following distributions:

RedHat Enterprise Linux 4.1
Fedora Core 4
SUSE Linux Enterprise Server 9.2 SP2

The RPMs come packaged in a single tar file for ease of installation. The tar file includes

The Xen hypervisor RPM
The XenLinux kernel RPM for the corresponding Linux distribution
The Xen-friendly glibc RPMs for the corresponding Linux distribution
The glibc that is being installed is just a recompiled version of the native one, using a gcc option that makes it more 'xen-friendly.' Xen kernels do run correctly using the native glibc, but performance is significantly impaired. If you don't want to install the Xen-friendly glibc, a (poor) alternative is to disable the thread-local storage (tls) handling features of glibc by hiding them, for example

mv /lib/tls /lib/tls.disabled

Source RPMs are also available for download, similarly packaged in a single tar file.

This document describes installing the Xen-enabled kernel for Xen 3.0 on a computer running any of the available distributions listed, and lists know issues, contact information, and pointers to more information.

Prerequisites

A system with one of the above-listed Linux distributions installed on it is the fundamental starting point.

GRUB is the only bootloader supported.

Installation

Important note for users with machines using the MPT Fusion SCSI interface: The Linux driver for this hardware has been changed slightly and now requires a different module. If you are currently running a kernel older than 2.6.16 (e.g. the Xen Linux kernel from Xen 3.0.1) then you will need to make a small change to /etc/modprobe.conf before you install the RPMs. You should currently have lines like:

alias scsi_hostadapter mptbase
alias scsi_hostadapter1 mptscsih

(with perhaps the second line missing). Replace these with:

alias scsi_hostadapter mptbase
alias scsi_hostadapter1 mptspi

(all other lines in the file remain unchanged) then continue with the installation as described below.

Quickstart Installation Instructions

Download the tar file from http://www.xensource.com/products/downloads/

As root:

cd /tmp

tar xvf tarfilename

cd tarfiledirectory

rpm -Fvh glibc*

rpm -Fvh nscd*

rpm -Uvh kernel*

rpm -Uvh xen-3.0.*

Detailed Installation Instructions

Download the compressed tar file from this site into a temporary working directory.
As root, cd to this directory and unpack the set of RPMs:
```
tar xvfz tarfilename
```
The RPMs will unpack into a directory similar in name to tarfilename
cd to this directory and type the command
```
rpm -Fvh glibc*
```
to install any glibc packages needed, and, if required,
```
rpm -Fvh nscd*
```
to install the modified Naming Service Caching daemon.
(the F argument freshens the glibc components that have changed if they are already present on the system, and installs it if it is not)
Type the command
```
rpm -Uvh kernel*
```
to install the Xen-enabled kernel (the U argument updates the kernel if it is already present on the system, and installs it if it is not).
Type the command
```
rpm -Uvh xen-3.0.*
```
to install the Xen hypervisor.

The system is now in a state equivalent to having built and installed Xen from source, or by installing the binary tarball, and updating glibc dependencies manually.

To continue, you need to edit your system's grub config and add a stanza for the Xen hypervisor.

Here is an example:

title Xen (2.6.12.6-xen3_2.1)
        root (hd0,0)
        kernel /xen-3.gz com1=115200,8n1
        module /vmlinuz-2.6.12.6-xen3_2.1 root=/dev/VolGroup00/LogVol00 
ro maxcpus=1 console=tty1 console=ttyS0,115200n8
        module /initrd-2.6.12.6-xen3_2.1.img

Installing the RPMs into a guest domain prior to boot

There are many ways that setting up a guest filesystem can be accomplished, but the following method is the preferred way.

Starting with a bare metal server, install the desired distribution into its own partition, leaving some unused disk space in another partition to hold the eventual guest filesystem.
Reboot the server off a LiveCD or otherwise reboot into a system other than the distribution you installed in the previous step.
Mount the root of the installed distribution's filesystem and the other partition.
Tar the entire filesystem of the installed distribution into a tar file on the partition that you want the guest domain to use.
Untar the tar file in place, which will create an image of the original root filesystem.
Change root to the partition where you put the tar file:
chroot /tardir
Run the RPM commands as described above
Change root back to your original filesystem root.

Known Issues

See the Known Issues page