A new year, a new blog engine.

While Wordpress is quite useful, its a heavy, hunking bit of software for those who just post occasionally and don’t really need any dynamic content at all. This is where Nikola comes into play.

Nikola takes posts in reST, Jupyter Notebook, YAML, TOML, Markdown or HTML and runs them through the theming engine to get plain, static HTML.

The benefit of this is almost zero load on your web server - as there is no dynamic data to process. Especially good for cheap VPS packages from the many online providers.

So far, I’m impressed!

After posting the last episode of the The Conversation Hour on the NBN, its been revisited.

This time with Tony Brown (Executive Manager, Corporate Media, NBN) and journalist Mark Gregory.

Enjoy.

Now we can use OpenVPN and the Yubikey + YubiCloud OTP service to do authentication for VPN connections.

Thanks to the OpenVPN team for fixing issues preventing this prior to v2.4.3.

More details on the page: OpenVPN OTP with a Yubikey

New guide up - right here.

My Xen servers main board didn’t have a second PWM controlled fan header to use with a PWM fan hub for the 3 case fans. Its a 4RU case - which has server grade 140mm fans that can draw up to 0.9A each and get up to around 3600 RPM.

So here’s how I used an ATTiny85 to generate a PWM signal from the variable ‘Speed Control’ voltage on pin 2 of the SYS_FAN header.

With the release of kernel-xen version 4.9.40, I have enabled CONFIG_TCP_CONG_BBR. This adds support for using BBR to improve the throughput from your servers (mostly web servers) to your clients.

If you run my kernel-xen package on your Xen guests, you can also take advantage of this new feature.

To enable, ensure you are running kernel-xen version 4.9.40 or above, then create a file called /etc/sysctl.d/enable-bbr.conf containing:

1
2

net.core.default_qdisc=fq
net.ipv4.tcp_congestion_control=bbr

You can activate this by typing: $ sysctl -p

The changes will automatically apply at the next system boot.

To read more about BBR and why it makes such a difference, head on over to acmqueue for a far more in-depth analysis than I could provide.