KVM

KVM on Centos

http://isborken.blogspot.com/2012/02/headless-kvm-setup-on-centos-62.html

Add VLAN to KVM guest

http://henroo.wordpress.com/2011/03/25/how-to-add-vlan-network-to-kvm-guest/

[root@root ~]# cat /etc/sysconfig/network-scripts

/ifcfg-br0

DEVICE="br0"

HWADDR="00:15:17:D3:B2:F0"

NM_CONTROLLED="no"

ONBOOT="yes"

IPADDR="192.168.16.191"

NETWORK="192.168.16.0"

NETMASK="255.255.255.0"

GATEWAY="192.168.16.1"

IPV6INIT=no

TYPE=Bridge

ifcfg-eth0 then just has BRIDGE=br0 - to connect to eth0 to this bridge

device

[root@root ~]# cat /etc/sysconfig/network-scripts/ifcfg-eth0

DEVICE="eth0"

HWADDR="00:15:17:D3:B2:F0"

NM_CONTROLLED="no"

ONBOOT="yes"

IPV6INIT=no

BRIDGE=br0

then other VMs can use the bridge device to configure their own virtual

interfaces with own IP numbers

but other VMs configure ifcfg-eth0 as per usual - as if its a separate

physical server

when creating the VM we specify br0 as the device it can use as network

adapter

[root@root ~]# cat scripts/virt-install.sh

virt-install \

-n myguest \

-r 2048 \

--vcpus=2 \

--os-variant=rhel6 \

-v \

--accelerate \

-c /var/lib/libvirt/images/CentOS-6.2-x86_64-minimal.iso \

-w bridge:br0 \

--vnc --vncport=7601 \

--disk path=/vm/guest.img,size=100

i cut and pasted the above as:

KVM Ubuntu

http://www.howtoforge.com/virtualization-with-kvm-on-ubuntu-11.10

actually there is virt-manager or something and nice GUI tools for KVM,

libvirtd etc - altho my steps below are for headless remote server

so use CLI tools like virsh

1. install libvirtd stuff

apt-get install ubuntu-virt-server python-vm-builder kvm-pxe bridge-utils

# virsh -c qemu:///system list

2. then reconfig the network for br0 as follows

# cat /etc/network/interfaces

auto lo

iface lo inet loopback

auto eth0

iface eth0 inet manual

#iface eth0 inet static

#address 192.168.15.48

#netmask 255.255.255.0

#gateway 192.168.15.2

auto br0

iface br0 inet static

address 192.168.15.48

netmask 255.255.255.0

network 192.168.15.0

broadcast 192.168.15.255

gateway 192.168.15.2

bridge_ports eth0

bridge_fd 9

bridge_hello 2

bridge_maxage 12

bridge_stp off

# /etc/init.d/networking restart

3. for convenience, put bootable image(s) in /var/lib/libvirt/images/

$ cp /opt/media/CentOS-6.2-x86_64-minimal.iso /var/lib/libvirt/images/

4. add VM admin users to groups - eg. evans, hentyw, henryh etc

# adduser user libvirtd

# adduser user kvm

5. make disk space for VMs - actually this is ideally on LVM volume so

one can resize VM's disks but i'm not that advanced yet

# mkdir /vm

# chgrp kvm /vm

# chmod 770 /vm

6. create a test VM

# cat scripts/virt-install.sh

virt-install \

-n myguest \

-r 256 \

--vcpus=1 \

--os-variant=rhel6 \

-v \

--accelerate \

-c /var/lib/libvirt/images/CentOS-6.2-x86_64-minimal.iso \

-w bridge:br0 \

--vnc --vncport=7601 \

--disk path=/vm/guest.img,size=10

actually you need to configure network interfaces to allow users to

reconfigure them - otherwise the above gives following permissions error:

ERROR Failed to add tap interface to bridge 'br0': Operation not

permitted

$ ls -lh /vm

total 0

-rwxrwxr-x 1 user user 10G 2012-04-17 15:38 guest.img

root@evans:/home/evans# virsh -c qemu:///system list

Id Name State

----------------------------------

1 myguest running

7. connect VNC console to running VM

see that vnc is up to connect a console to the VM - you should see

install screen as per the ISO we have specified for the CDROM eg. CentOS

above

# netstat -ntl | grep 7601

tcp 0 0 127.0.0.1:7601 0.0.0.0:* LISTEN

# telnet localhost 7601

Trying ::1...

Trying 127.0.0.1...

Connected to localhost.

Escape character is '^]'.

RFB 003.008

# virt-viewer myguest