lvcache: a tool for managing LVM caches

Sat 16 August 2014 by Lars Kellogg-Stedman Tags lvm cache

Until recently I had a bcache based setup on my laptop, but when forced by circumstance to reinstall everything I spent some time looking for alternatives that were less disruptive to configure on an existing system.

I came across Richard Jones' article discussing the recent work to integrate dm-cache into …

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Four ways to connect a docker container to a local network

Mon 11 August 2014 by Lars Kellogg-Stedman Tags networking docker openvswitch

This article discusses four ways to make a Docker container appear on a local network. These are not suggested as practical solutions, but are meant to illustrate some of the underlying network technology available in Linux.

If you were actually going to use one of these solutions as anything other …

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gpio-watch: Run scripts in response to GPIO signals

Sat 26 July 2014 by Lars Kellogg-Stedman Tags raspberrypi gpio

For a small project I'm working on I needed to attach a few buttons to a Raspberry Pi and have some code execute in response to the button presses.

Normally I would reach for Python for a simple project like this, but constraints of the project made it necessary to implement something in C with minimal dependencies. I didn't want to write something that was tied closely to my project...

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Tracking down a kernel bug with git bisect

Mon 21 July 2014 by Lars Kellogg-Stedman Tags docker kernel git

After a recent upgrade of my Fedora 20 system to kernel 3.15.mumble, I started running into a problem (BZ 1121345) with my Docker containers. Operations such as su or runuser would fail with the singularly unhelpful System error message:

$ docker run -ti fedora /bin/bash
bash-4.2# su …
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Booting an instance with multiple fixed addresses

This article expands on my answer to Add multiple specific IPs to instance, a question posted to ask.openstack.org.

In order to serve out SSL services from an OpenStack instance, you will generally want one local ip address for each SSL virtual host you support. It is possible to …

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