Articles posted on 2019

Python Virtual Environments

This is the least you need to know to get to use a Python virtual environment. What is a Virtual Environment At its core, the main purpose of Python virtual environments is to create an isolated environment for Python projects. This means that each project can have its own dependencies, regardless of what ...

Calculate system availability

To calculate the availability of redundant systems you can use this formula: total_avail = 1-(1 - single_avail) ^ (number_of_nodes) Nodes: ...

Ad-Hoc rsync daemons

The other day I needed to copy a bunch of files between to servers in my home network. Because of the volume I wanted to copy the files without having to go through ssh's encryption overhead. So I figured I could use netcat for the data transport. To do that I wrote these short scripts. Remote scripts ...

Resizing Virtual Disks with virsh

I am currently using libvirt for managing my VMs. For virtual discs I am using LVM2 volumes. On a regular basis I need to resize these virtual discs, but not that often that I can do this from memory. This is a short procedure to do this: ls -l /dev/vgX/lvX # note down the major/minor numbers for later lvextend -L +50G /dev/vgX/lvX # adding 50GB to this volume ...

Z-Wave Associations with With Vera UI

I couldn't find any to the point documentation on how to do this, so I am writing this. The way I understand Z-Wave associations work is that once devices are in the same Z-Wave network, a device can directly send a command to another device without intervention of the Hub or controller. ...

Encrypting FileSystem in Void Linux

The point of this recipe is to create a encrypted file sytem so that when the disc is disposed, it does not need to be securely erased. This is particularly important for SSD devices since because of block remapping (for wear levelling) data can't be overwritten consistently. The idea is that the boot/root filesystem containing the encryption ...

Installing Void Linux

I made the switch to void linux. Except for compatibility issues around glibc, it works quite well. Most compatibility I have worked around with a combination of Flatpaks, chroots and namespaces. The high lights of void linux: ...