Getting started with KVM Bridging

I have KVM VMs running on RHEL5.4 but I don't have networking set up yet. My plan was to add another bridge (since virbr0 is a default virtual bridge), connect eth0 to it and then connect my VMs to it with virsh net-define, net-create, ..., etc. However, I seem to have misunderstood something:

[root@kvm-dev0 ~]# brctl addbr virbr1
[root@kvm-dev0 ~]# 

[root@kvm-dev0 ~]# brctl show
bridge name     bridge id               STP enabled     interfaces
virbr0          8000.5690886c5cfa       yes             vnet2
                                                        vnet0
                                                        vnet1
virbr1          8000.000000000000       no
[root@kvm-dev0 ~]#

[root@kvm-dev0 ~]# brctl addif virbr1 eth0
[root@kvm-dev0 ~]# 

Looks like I locked myself out with the command above. Looks like no more playing on this box (yes, it's only a development system) until I get back to the office. Looks like I'll have to do more reading.

Haydn Solomon's KVM blog has an entry on bridged networking. Gavin Carr's blog has a quick guide to KVM bridging.

Update: as per wiki.libvirt.org, adding eth0 to virbr0 is not something that is ever necessary. I did the above out of confusion.

RedHat Doc updates

The Virtualization Guide for RHEL 5.4 discusses KVM and Xen as opposed to the 5.3 document. The GFS2 doucment has also been updated.

Vixie article on DNS

A friend sent me this Vixie article on DNS. I haven't read it all, but what I read so far is good so I'll link to it and remember to read more later.

Ubuntu 9.10 boot problem

I upgraded my workstation from Ubuntu 9.04 to 9.10. I got the alert dev disk by-uuid does not exist dropping to a shell error. The fix was to use the busybox shell to mount /dev/sda1 (in the case of my system) on /foo and then "chroot /foo /bin/bash". I then updated:

1. /etc/fstab
Replace "UUID=f3920f76-f982-47b0-b2e7-8d6536482b8f" with "dev/sda1"

2. /boot/grub/menu.lst
Replace the UUID with the device as above. I also took out "quiet splash".

I was then able to reboot.