Kvm on BAFM

Debian: dmesg output contains Error: Driver 'pcspkr' is already registered, aborting…

Tue, 28 Feb 2017 15:18:42 +0000

Well, I recently prepared a bunch of Debian KVM guests, and today I got annoyed (basically because logwatch complains about it …) by this pesky error message on each startup. What causes this is error is really simple.

Udev loads the PC speaker driver (pcspkr) and then (for whatever reason) tries to load the alsa-module for the PC speaker (snd_pcsp). And the second one, basically fails. All we need to do, is create a blacklist.conf and add the latter one to it.

Hetzner, Debian, KVM and IPv6

Mon, 25 Aug 2014 20:08:11 +0000

Well, I’ve had my share of troubles with Hetzner, Debian, KVM and IPv6 addresses. After figuring out how to get around the IPv6 neighbor stuff (npd6 for teh win!), I battled with the problem that after restarting (rebooting/resetting - doesn’t really matter) a domain it’s IPv6 address would no longer work.

Well, today I decided to take a closer look. After the reboot, the guest comes up with this:

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pinguinfuss:(thanatos.heimdaheim.de/webs) PWD:~
Mon Sep 09, 19:01:27 [0] > ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN
 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
 inet 127.0.0.1/8 scope host lo
 inet6 ::1/128 scope host
 valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
 link/ether 52:54:00:96:ed:35 brd ff:ff:ff:ff:ff:ff
 inet 78.46.37.114 peer 78.46.37.118/32 brd 78.46.37.114 scope global eth0
 inet6 2a01:4f8:110:3148::5/64 scope global tentative dadfailed
 valid_lft forever preferred_lft forever
 inet6 fe80::5054:ff:fe96:ed35/64 scope link
 valid_lft forever preferred_lft forever

A quick peek into ip 6 neigh show reveals this:

Hetzner KVM guest networking

Mon, 17 Jun 2013 16:39:48 +0000

Now, since we’re using bridged routing, we need to adjust the guest.

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auto eth0
iface eth0 inet static
 address 78.46.37.114
 netmask 255.255.255.255
 pointopoint 78.46.37.118
 gateway 78.46.37.118
 post-up ping -c2 78.46.37.118 &>/dev/null

iface eth0 inet6 static
 address 2a01:4f8:110:3148::5
 netmask 64
 gateway 2a01:4f8:110:3148::2
 post-up ping6 -c2 2a01:4f8:110:3148::2 &>/dev/null

This’ll take care of the bridged routing and the ICMPv6 announcement to the host. Without the ping/ping6, guest and host won’t be able to communicate (no clue why).

Hetzner KVM host bridge configuration

Mon, 17 Jun 2013 16:37:41 +0000

Firstoff, adjust the /etc/network/interfaces file to look like this:

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# device: eth0
auto eth0
iface eth0 inet static
 address 78.46.37.118
 netmask 255.255.255.255
 gateway 78.46.37.97
 pointopoint 78.46.37.97

iface eth0 inet6 static
 address 2a01:4f8:110:3148::2
 netmask 64
 gateway fe80::1

auto vmbr0
iface vmbr0 inet static
 address 78.46.37.118
 netmask 255.255.255.255
 bridge_ports none
 bridge_stp off
 bridge_fd 0
 post-up ip route add 78.46.37.108/32 dev vmbr0
 post-up ip route add 78.46.37.110/32 dev vmbr0
 post-up ip route add 78.46.37.114/32 dev vmbr0

iface vmbr0 inet6 static
 address 2a01:4f8:110:3148::2
 netmask 64
 post-up ip -6 neigh add proxy 2a01:4f8:110:3148::3 dev eth0
 post-up ip -6 neigh add proxy 2a01:4f8:110:3148::4 dev eth0
 post-up ip -6 neigh add proxy 2a01:4f8:110:3148::5 dev eth0
 post-up ip -6 neigh add proxy 2a01:4f8:110:3148::6 dev eth0
 post-up ip -6 neigh add proxy 2a01:4f8:110:3148::7 dev eth0
 post-up ip -6 neigh add proxy 2a01:4f8:110:3148::8 dev eth0
 post-up ip -6 neigh add proxy 2a01:4f8:110:3148::9 dev eth0

Secondly, adjust you KVM guest network config to look like this (similar, you might want to replace the MAC address of the guest):

virt-viewer: qemu+ssh to a KVM host running SSH on a different port

Wed, 12 Jun 2013 18:26:54 +0000

Well, I’ve been tinkering with KVM the last few days and I’ve been stuck accessing the KVM guests (as the guests are running on a host I don’t have my Xorg server running on). After a bit of searching, I actually found what I was looking for.

Piecing together from both sources, to connect to a KVM host, that has SSH running on a different port:

`1`	`virt-viewer --connect qemu+ssh://root@kvm.home.barfoo.org:222/system guest`