Articles | johnlewis.ie

By: John Lewis  05/12/2011

Trawling through the various mailing lists reveals that “network biopair”, whatever that is, has been removed from Postfix as of December 2010, v2.8. Admittedly a bit of a long shot, I decided “what the hey” upgrading to Postfix 2.8 isn’t going to make things any worse, and it may sort the problem out.

The next problem then was how to upgrade to version 2.8, my mail server runs as part of an LXC container. Upgrading LXC containers is difficult because new versions of upstart, udev, ifupdown et al like to recreate device nodes, change init scripts and what not. Assuming you’re able to successfully complete the upgrade you will still probably be left with a container which doesn’t boot properly, or at all. I was hoping to stay with Lucid Lynx in the container, until support runs out, in the hope that the LXC boys would have made upgrades smoother by then, but how could I easily update to version 2.8 without either running from source, or running the gauntlet of the container upgrade? Further googling revealed that version 2.8 is available via backports so in /etc/apt/sources.list I added the following line and upgraded:-


deb http://ie.archive.ubuntu.com/ubuntu/ lucid-backports main restricted universe multiverse

It’s too early to say whether the problem is completely fixed. If it isn’t I will remove this post!


Other products and services from John Lewis

05/12/2011

Articles | johnlewis.ie | Page 2

Saorview can be received through a standard wide-band UHF aerial, there will be an accompanying satellite service for people who are unable to receive the terrestrial signal but it hasn’t even launched in trial form yet and will require the purchase of more equipment in the form of a special satellite dish and receiver.


05/12/2011

Articles | johnlewis.ie | Page 3

In other words if you aren’t a perfect admin and manage to accidentally lock yourself out by putting an iptables rule in wrong, iptables-apply will automatically revert back to the previous set of rules and you’ll get access again. Iptables-apply is a script that applies firewall rules and then waits a configurable amount of time, for user input, to confirm the changes were successful.


05/12/2011

Articles | johnlewis.ie | Page 4

Unfortunately I found out after much head banging and googling “magic packet” doesn’t work over wireless networks, apparently because wireless frames screw the magic packet up so that the wakee doesn’t recognise it any more. So if you want to use WOL by sending the wake up through a wireless network your options are limited and it depends on the network card you have.