Designing High-Availability for Xen Virtual Machines with HP Serviceguard for Linux

Note: Citrix XenSource is currently not supported.

Packaging the Xen virtual machine with Serviceguard for Linux

Creation of Xen VM and dependencies

A Xen VM guest can be created using ‘virt-install’ (Redhat) or ‘vm-install’ (Novell). The

VM install script prompts for the following information at the time of installation:

• VM types: fully-virtualized (FV) or para-virtualized (PV). For detailed information on

the VM types, refer to Xen Administration Guide [4]

• Storage: Virtual Disk or Physical Shared Disk as the primary disk for the guest OS

• Network: Virtual Network Interface (An Internet protocol address is configured for the

Xen VM at the time of guest OS installation)

• Installation Repository for guest OS: nfs, ftp, http, cdrom, iso

The ‘virt-install/vm-install’ script creates a Xen VM guest configuration file to store

configuration information for the guest VM. The ‘virt-install/vm-install’ picks up the boot

image from the install repository and boots the guest VM into install mode. The installation of the OS

proceeds as usual on the guest VM.

After installation of the guest OS, the guest VM can be started using the command

xm create <absolute path to guest configuration file>

and shutdown using the commands

xm shutdown <name of guest configuration file>

See the section “Xen Control and Management” to learn more about the management commands.

To provide high availability to the Xen virtual machine guests running on the Xen host, the Xen VM

must be registered as an SG/LX package. In order to do this, the following requirements must be met:

• The Xen VM guest configuration file must reside on a volume group on the shared storage. All

default paths in the Xen VM guest configuration file must be adjusted to reflect the new

location of the Xen VM files (virtual disks, config files etc.)

• If a Xen VM uses a virtual disk, it must reside on a volume group on the shared storage. If a

Xen VM uses a physical disk, the physical disk must be located on the shared storage. This

ensures that the Xen VM storage is available from other nodes when a Xen VM package fails

over

• In the case of the SG/LX legacy package used in the examples in this paper, the package

control script must be created, modified and applied. (See the latest version of Managing

Serviceguard for Linux for information about legacy versus modular packages.)

Consolidate all Xen Guest VM files in one Volume Group

When creating a Serviceguard for Linux package for the Xen VM, you need to identify all of the

resources used by the Xen VM and include them in the package.