Specifications

21. Cloning the Guest Configuration Files

You can copy (or clone) an existing configuration file to create an all new guest. You must

modify the name parameter of the guests' configuration file. The new, unique name then

appears in the hypervisor and is viewable by the management utilities. You must generate an all

new UUID as well (using the uuidgen(1) command). Then for the vif entries you must define

a unique MAC address for each guest (if you are copying a guest configuration from an existing

guest, you can create a script to handle it). For the xen bridge information, if you move an

existing guest configuration file to a new host, you must update the xenbr entry to match your

local networking configuration. For the Device entries, you must modify the entries in the

'disk=' section to point to the correct guest image.

You must also modify these system configuration settings on your guest. You must modify the

HOSTNAME entry of the /etc/sysconfig/network file to match the new guest's hostname.

You must modify the HWADDR address of the

/etc/sysconfig/network-scripts/ifcfg-eth0 file to match the output from ifconfig eth0

file and if you use static IP addresses, you must modify the IPADDR entry.

22. Creating a Script to Generate MAC Addresses

Red Hat Virtualization can generate a MAC address for each virtual machine at the time of

creation. Since is a nearly unlimited amount of numbers on the same subnet, it is unlikely you

could get the same MAC address. To work around this, you can also write a script to generate a

MAC address. This example script contains the parameters to generate a MAC address:

#! /usr/bin/python

# macgen.py script generates a MAC address for Xen guests

import random

mac = [ 0x00, 0x16, 0x3e,

random.randint(0x00, 0x7f),

random.randint(0x00, 0xff),

random.randint(0x00, 0xff) ]

print ':'.join(map(lambda x: "%02x" % x, mac))

Generates e.g.:

00:16:3e:66:f5:77

to stdout

23. Configuring Virtual Machine Live Migration

Red Hat Virtualization can migrate virtual machines between other servers running Red Hat

Enterprise Linux 5.1 with Virtualization. Further, migration is performed in an offline method

(using the xm migrate command). Live migration can be done from the same command.

Cloning the Guest Configuration Files