I was working on my laptop and realize that I was seeing the errors “device-mapper: ioctl: error adding target to table” and “device-mapper: table: 253:1: linear: dm-linear: Device lookup failed” flood my logs. My CPU usage was also extremely high. Apparently this is an issue with EVMS and recent Linux kernels. There are a couple ways to resolve this.

Traffic shaping is one of those topics that most people find mystifying when they attempt to research it. I’ve been doing traffic shaping work for years and I still find myself learning new things. I thought with some recent work I’d write down a few notes on practical setups for Linux using the tc (traffic control) command. I also want to highlight some common issues people need to address when designing traffic control systems.

For better or worse I’ve been needing to check drives for errors quite a bit recently and have been using the badblocks command to do it. It’s definitely a command that people should become familiar with. Where fsck checks the file system for problems, badblocks attempts to ascertain the status of physical media which can include hard disks, usb drives, and other usb devices such as media players. I’ve compiled a detailed list of commands I’ve been using.

There's something you don't see a lot of: an openssh vulnerability. Time to patch those clients. Details can be found at: USN-566-1: OpenSSH vulnerability. The vulnerability has to do with X11 forwarding which I always disable so I assume my systems are safe but I will still upgrade promptly.