Monday, April 30, 2007

recept: schandalige chocolademelk

Neem 3 stukjes 99% cacao lindl chocolade. Doe in een beker. Giet er wat ahorn siroop bij. Vul de beker met melk. Ongeveer 2 minuten in de microgolf oven op 900 Watt.
Blijf bij de microgolf staan en stop hem als het net niet overkookt.
Wacht een seconde en start de microgolf weer, en stop weer als het net niet overkookt.
Doe dit een keer of 4.
Eventueel wat roeren.
Nu zou de chocolade perfect opgelost moeten zijn.

debian in kvm mini howto

I started by downloading the debian-40r0-i386-CD-1.iso via jigdo.
Then I created a disk image file like this:

qemu-img create vdisk.qcow 1G

Then I boot kvm like this:

kvm -hda vdisk.qcow -cdrom debian-40r0-i386-CD-1.iso -boot d -m 256

(It may be needed to change the permissions of /dev/kvm)

Proceed with installation as a normal debian installation. I only installed the minimum.
The default kvm uses a build-in user space networking. However I'd like to have bridged
networking.
First I create a tap0 device in /etc/network/interfaces:

iface tap0 inet manual
pre-up tunctl -b -u <my_user_name> -t tap0
pre-up ifconfig tap0 up
post-down tunctl -d tap0

Make sure you have tunctl installed, its part of the uml-utilities package.
Replace the <my_user_name> by the user you want to run kvm as.
Normally my network interface is configured via DHCP, soo I want to keep that.
However I want kvm to be also able to access my LAN. Therefor I create a bridge interface:

iface br0 inet dhcp
bridge_ports eth0 tap0
bridge_maxwait 0

Which I bring up via DHCP. Of course I'll have to change eth0 also:

iface eth0 inet manual

Finually make sure they are brought up in the right order:

auto lo eth0 tap0 br0

In total this gives an /etc/network/interfaces like this:

auto lo eth0 tap0 br0

iface lo inet loopback

iface br0 inet dhcp
bridge_ports eth0 tap0
bridge_maxwait 0

iface eth0 inet manual

iface tap0 inet manual
pre-up tunctl -b -u <my_user_name> -t tap0
pre-up ifconfig tap0 up
post-down tunctl -d tap0

Finually edit the file /etc/kvm/kvm-ifup and put everything in it in comments.
Now bring down the network and bring it up again:

ifdown -a
ifup -a

And then start the kvm:

kvm -net nic -net tap,ifname=tap0 -hda vdisk.qcow -m 256 -localtime

Once booted, log in and change the /etc/network/interfaces file in the image to use DHCP:

iface eth0 inet dhcp

If you bring down the net and bring it up again (within the kvm!):

ifdown -a
ifup -a

you should get a DHCP lease from your LAN and the kvm is available on the LAN.

Now it's time to start using it!