Running 512 containers on a laptop

LXC is a management system for lightweight virtual machines called containers. LXC relies on the Linux kernel for several key features including process isolation and resource limitation. Compared to virtual machines, LXC containers have a few limitations, however none of them affect the vast majority of use cases. My laptop (Thinkpad X220) is by no measure a speed demon, although it still has the required resources to host a seemingly arbitrarily large amount of containers thanks to a few key deduplication technologies.

IRSSI Push notifications to GNOME desktop and Android device

IRSSI configuration Install these scripts into $HOME/.irssi/scripts (and symlink it in $HOME/.irssi/scripts/autorun) to have them autoloaded when IRSSI starts. screen_away.pl notifonotify.pl socketnotify.pl Android configuration Sign up for a notifo account, download the android app, and sign in with it. Make note of the username and API key, as you’ll be configuring irssi to use them. You’ll be loading the scripts in IRSSI and setting 2 notifo parameters: /script load screen_away.pl /script load socketnotify.

Ganeti, dealing with node failure

Get paged Stop panicking Be sure to log into the broken node to verify it actually died. If the VMs are still running correctly on it, and it’s simply a networking problem, if you proceed to bring them up again you will encounter a bad state known as ‘Split Brain’. This is difficult to recover from, so please verify the dead node is truly dead. If there is more than 1 node left, try logging into the cluster IP (kvm.

Sharp Netwalker Ubuntu Lucid Image

I wanted a recent Ubuntu distribution though, which I couldn’t find provided for me online. So I rolled my own, and am reasonably pleased with the results. All of the hardware works, although there are some annoyances, such as no battery meter in the GNOME notification area, and the wireless card isn’t supported by NetworkManager, although still works with iwconfig and wpasupplicant. Additionally, the hotkeys on the top are not bound to any programs.

Upgrading GuruPlug Kernels

After a failed flashing attempt(don’t attempt to tftp flash u-boot.kwb from within U-Boot!) I needed to use JTAG combined with the included JTAG adapter. To do this, make sure that the UART cable is unplugged, and the JTAG cable is plugged in(unplug/replug the USB adapter just to be safe). First grab the guruplug-installer package, then grab a known-good copy of U-Boot. $ cd Downloads/ $ tar zxvf Guruplug-installer.tar.gz $ cd guruplug-installer $ sudo .

Defcon Badge Hackery

Some of the OSUOSL employees attended the recent DefCon 18 conference. One of the more uncommon features was the conference badge. In addition to being a ticket for entry into the conference, it’s also a hackable piece of hardware complete with 128×32 LCD screen, and microprocessor. The source code for the badge is available online. Corbin Simpson, a developer at the OSU Open Source Lab spent a large portion of his time at the conference developing and uploading new software onto his badge.

Restoring GuruPlugs

At which point I decided I wanted to try to restore the original kernel, so that I would at least have a working system with which to test. Therein lied the rub. The files posted here are completely broken. Thankfully, a friend of mine also ordered a GuruPlug. So I grabbed his images. Here’s how to ACTUALLY restore your GuruPlug if you flash a bad kernel to it. Download the extracted uImage.