Running (Almost) Anything in LXC: The Basics

Posted on Mon 28 December 2020 in hints-and-kinks • Tagged with LXC

LXC is part of my standard Linux desktop toolbox, and I use it daily. I have done tutorials about this before, one of which you can find on YouTube (courtesy of linux.conf.au) and GitHub, but it’s about time I included this in a series of articles.

My …


Continue reading

Celery to Chew On

Posted on Wed 06 May 2020 in hints-and-kinks • Tagged with Django, MySQL, HAProxy, Celery, Python

Asynchronous Celery tasks that manipulate a MySQL/Galera database from a Django application can produce very interesting behavior when HAProxy is involved.


Continue reading

Ceph Erasure Code Overhead Mathematics

Posted on Sat 30 November 2019 in hints-and-kinks • Tagged with Ceph

In a Ceph cluster, the frequent question, “how much space utilization overhead does my EC profile cause,” can be answered with very simple algebra.


Continue reading

Using ftrace to trace function calls from qemu-guest-agent

Posted on Wed 21 August 2019 in hints-and-kinks • Tagged with libvirt, Linux, ftrace, Qemu

When you are using functionality that is buried deep in the Linux kernel, ftrace can be extremely useful. Here are some suggestions on how to use it, using the example of tracing function calls from qemu-guest-agent.

What’s this about?

Recently I used, for the first time, libvirt’s functionality …


Continue reading

Configuring CLI output verbosity with logging and argparse

Posted on Wed 01 May 2019 in hints-and-kinks • Tagged with Python

Command-line interfaces frequently produce output whose verbosity your users may want to be able to tweak. Here’s a nifty way to do that.


Continue reading