Firewalling an OpenVZ node and containers

The OpenVZ wiki has a nice script for firewalling an OpenVZ node and it’s containers. It creates a service and configures iptables to block all traffic to the node (except the ports you specify), but allow all traffic through to the containers, so that they can manage their own firewall. It also allows the container’s […]

Content Above Anchors Disappear

It turns out there’s a serous problem with the One True Layout method of creating equal height columns. All of the content above an anchor will be shifted up, making it seem like it disappeared. There aren’t any universal or reliable fixes for this, so the Faux Columns method is probably the best choice if […]

Working with Qmail’s Queue

qmqtool is a great tool for viewing and changing messages in qmail’s queue. It’ll help you search for and delete spam, for instance. The FAQ has a some examples to get started with.

Relaying Qmail Through a Spam Filter

If you’re running a mail service on a web server so it can send out e-mail from contact forms, etc then you’ll want to make sure it’s relaying outbound mail through a spam filter, or it could be used to send spam if the forms get hijacked. For qmail, you just need to create /var/qmail/control/smtproutes […]

Memorable IP Address

If you’re troubleshooting a network’s uplink to the Internet and want a memorable external IP address to ping, then you can use 4.2.2.2, which is one of Verizon’s DNS servers.

Skipping Disk Check When Rebooting Linux Server

If you don’t run a disk check on a Linux server in awhile and you reboot, it may force a disk check, which can take 30+ minutes, and it’ll be offline the entire time. You can reboot and skip the check with shutdown -fr now or force a check with shutdown -Fr now. (via go2linux.org)

Natural Sorting for MySQL

MySQL doesn’t provide a way to perform natural sorting on a string, so if you have numbers in your data you may get results like this Product 110 Product 120 Product 13 Product 140 There are a lot of hacks available, but all of the ones I’ve seen only work in specific circumstances. The only […]

Ian Dunn

WordPress Developer

Firewalling an OpenVZ node and containers

Content Above Anchors Disappear

Working with Qmail’s Queue

Relaying Qmail Through a Spam Filter

Memorable IP Address

Skipping Disk Check When Rebooting Linux Server

Natural Sorting for MySQL