hosted services

I've grown accustom to a few things being just the way that I like them. Below are a few things I've done with the current VM where I've needed to do a couple of work-arounds to make things feel more the way that I'm used to.

console

Had this problem with Xen, needed to run getty on the console but it wasn't configured, so I did this:

/etc/inittab:

co:2345:respawn:/sbin/getty 38400 xvc0

date time on host

After the VM was moved to another host I noticed that the host's sysop had incorrectly set the clock forward one hour. After several attempts to explain this situation to the SysOp I decided to do some research. I was under the impression that the system clock had to be controlled by the host physical server and that VM's were not able to control the clock, this was largely based on the output one gets when attempting to change the clock.

The value held in /proc/sys/xen/independent_wallclock controls the boolean for user VM's having their own clocks.

This is really ideal when the host can't update the clock.

# echo 1 > /proc/sys/xen/independent_wallclock
# ntpdate ntp.demon.co.uk
21 Nov 10:20:34 ntpdate[16623]: step time server 158.152.1.76 offset -3605.968002 sec

The next thing I immediately did was to re-configure the clock to Europe/London, the easiest method of doing is is to run

# dpkg-reconfigure tzdata

debian

Xen works very well with Debian, in fact, I'd go so far as to say that I prefer Xen to VirtualBox these days. There

As my desktop has a cheap wireless USB network device it refuses to release packets to the network that are not from its own MAC, quite disappointing. So therefore networking has to be accomplished via a bridge and NAT.

This can be done like so:

# brctl addbr br0
# ifconfig br0 10.0.0.1 netmask 255.255.255.0 up

You'll need to enable forwarding

echo 1 > /proc/sys/net/ipv4/ip_forward

along with NAT and NAT (post routing and masquerade) with iptables

# iptables -A FORWARD --in-interface br0 -j ACCEPT
# iptables --table nat -A POSTROUTING --out-interface wlan0 -j MASQUERADE

Add the following to your configuration file, something like:

vif = [ 'type=ioemu, bridge=br0' ]

From your domainU it will now be possible to add the network interface, within the /24 segment, like so:

# ifconfig eth0 10.0.0.2 netmask 255.255.255.0 up
# route add default gw 10.0.0.1