Messing with KVM as a replacement for my Microserver setup at home.  With KVM, you can define a thin-provisioned VM image file (a qcow2 file), which is a sparse file on the filesystem.  You can then configure the guest O/S so that TRIM support works, and it can then unmap unused blocks by the guest FS and have those blocks get unmapped the whole way down the stack (released from the sparse file, and ultimately trimmed from the underlying SSD if there is one).

I picked up a few LoLin NodeMCU v3 boards the other day (you can read a comparison of the various NodeMCU dev boards here).  However, I had a hiccup with it.

Last post I mentioned how I got an ESP8266 board.  Well, I’ve put together that with a DHT11 and MQTT to create a widget that senses temperature and humidity, then posts that on a regular basis to your MQTT message broker.  The data comes out in JSON format for ease of use.  I’ll cover the hardware later, once I get the rest of my prototype boards.

The ESP8266 is a ridiculously cheap ($2 or so from China), WiFi equipped breakout board which has a 32-bit microcontroller and Flash (1MB) onboard.  It comes in a bunch of different versions (mine is an ESP-01), and all with different Flash capacities.  The pinout of the one I have appears below;

Recently picked up a Ralink 7601 Wifi Adapter (a no-name clone wifi stub from Ebay), for the princely sum of about $2 delivered.  It’s identifable easily because in lsusb it shows up as;

With the release of LetsEncrypt to the public, I’ve reconfigured my blog server to use HTTPS.  Setup was pretty straightforward, I just followed the nginx setup guide.  Notably though, my highly restrictive nginx setup didn’t work with the rules they described.  Instead, I needed this fragment to get the Let’s Encrypt authentication challenge to pass;