Virtualization short cuts for noobs

Virtualization short cuts for noobs

Introduction

References

http://www.linux-kvm.org/page/Documents

KVM documentation page.

http://www.linuxfoundation.org/collaborate/workgroups/networking/bridge

description of the linux bridge implementation.

http://en.gentoo-wiki.com/wiki/Bridging_Network_Interfaces

http://en.gentoo-wiki.com/wiki/KVM#Networking_2

Shows direct and indirect bridging.

http://blog.loftninjas.org/2008/08/18/using-attach-interface-with-libvirt-and-qemukvm-on-ubuntu/

about attach-interface.

http://tjworld.net/wiki/Linux/Ubuntu/VirtualMachinesWithVDENetworking

Virtual Machines With VDE Networking

http://www.mythicalbeast.co.uk/linux/dnsmasq_howto.html

HOWTO for dnsmasq

Open issues

how to pin Dom0

How do we pin Dom0 to a specific CPU?

Operating Environment

Which packages you need in order to run virtualization.

Storage

• File based
• LVM Based
• NFS based
• iSCSI

Network

Network configuration needs.

• Bridging
  • Direct
  • NAT
• NAT/Route

Get direct bridging

Looks better: [Guest Configuration on Fedora 12 with Netcf] Source: [KVM w/o dnsmasq on CentOS 5.2 X64].

1. cd /etc/sysconfig/network-scripts
2. mkdir bak
3. cp -p ifcfg-eth0 bak
4. virsh iface-dumpxml eth0 > bak/eth0.xml
5. cp bak/eth0.xml bak/kvmbr0.xml
6. vi bak/kvmbr0.xml
7. virsh iface-define bak/kvmbr0.xml
8. virsh iface-list
9. service network restart
10. virsh edit fc13_1
11. brctl show

The following didn't cut it, it simply prevented the DomU in starting, due to the missing 'default' network...

1. virsh net-destroy default
2. virsh net-autostart --disable default

1. virsh net-autostart default

virsh net-dumpxml default

<network>
  <name>default</name>
  <uuid>4eb269bb-b949-49ae-95b1-6e281b634c47</uuid>
  <forward mode='route'/>
  <bridge name='virbr0' stp='on' delay='0' />
  <ip address='192.168.122.1' netmask='255.255.255.0'>
    <dhcp>
      <range start='192.168.122.2' end='192.168.122.254' />
    </dhcp>
  </ip>
</network>

Administration

virsch

virsh help lists the supported commands.

See also [28. Managing guests with virsh]

Virsh operations commands of interest

console

get access to the console in the DomU.

destroy

as if you pulled the power cord, preferably use 'shutdown'.

reboot

reboot the domain.

shutdown

shutdown the domain.

undefine

remove all references to the domain. (Note; not sure if it is actually *all*).

dumpxml

list

List the active domains. Use '--all' to include the the inactive containers to the list.

Virsh network commands of interest

domifstat

interface statistics.

• virsh domifstat z3 vif7.0

attach-interface

attach a network interface.

• virsh attach-interface z3 bridge eth1 --target eth1 --mac xx:xx:xx:xx:xx:xx

net-edit

For an description of the xml structure see: [XML format]

net-list

list networks.

Creating DomUs

Creating a CentOS 5.5 DomU

source:NFS, storage:LVM network:bridge;4

virt-install -p --name=z4 --ram=512 --vcpus=1 --disk path=/dev/loom/z4 --os-type=linux --os-variant=rhel5 --location=nfs:192.168.42.132:/exports/isos/centos55 -x "ks=nfs:192.168.42.132:/exports/ks/anaconda-ks.cfg ip=192.168.42.31 netmask=255.255.255.0 gateway=192.168.42.132 dns=192.168.42.32"