Managing KVM virtual machines part II – the libvirt toolkit

In the previous post, we have seen how Vagrant can be used to define, create and destroy KVM virtual machines. Today, we will dig a bit deeper into the objects managed by the libvirt library and learn how to create virtual machines using the libvirt toolkit directly Creating a volume When creating a virtual machine, … Continue reading Managing KVM virtual machines part II – the libvirt toolkit

OpenStack Cinder foundations – building logical volumes and snapshots with LVM

When you want to build a volume service for a cloud platform, you need to find a way to quickly create and remove block devices on your compute nodes. We could of course use loopback devices for this, but this is slow, as every operation goes through the file system. A logical volume manager might … Continue reading OpenStack Cinder foundations – building logical volumes and snapshots with LVM

OpenStack Cinder foundations – storage networks, iSCSI, LUNs and all that

To understand Cinder, the block device component of OpenStack, you will need to be familiar with some terms that originate from the world of data center networks like SCSI, SAN, LUN and so forth. In this post, we will take a short look at these topics to be prepared for our upcoming installation and configuration … Continue reading OpenStack Cinder foundations – storage networks, iSCSI, LUNs and all that

Building your own cloud with OpenStack – overview

Over time, I have worked with a couple of different commercial cloud platforms like AWS, DigitalOcean, GCP, Paperspace or Packet.net. Even though these platforms are rather well documented, there comes a point where you would like to have more insights into the inner workings of a cloud platform. Unfortunately, not too many of use have … Continue reading Building your own cloud with OpenStack – overview

Virtual networking labs – building a virtual router with iptables and Linux namespaces

When you are trying to understand virtual networking, container networks, micro segmentation and all this, sooner or later the day will come where you will have to deal with iptables, the built-in Linux firewall mechanism. After evading the confrontation with the full complexity of this remarkable beast for many years, I have recently decided to … Continue reading Virtual networking labs – building a virtual router with iptables and Linux namespaces

Virtual networking labs – Open vSwitch in practice

In the last post, we have discussed the architecture of Open vSwitch and how it with a control plane to realize an SDN. Today, we will make this a bit more tangible by running two hands-on labs with OVS. The labs in this post are modelled after some of the How-to documents that are part … Continue reading Virtual networking labs – Open vSwitch in practice

Virtual networking labs – a short introduction to Open vSwitch

In the previous posts, we have used standard Linux tools to establish and configure our network interfaces. This is nice, but becomes very difficult to manage if you need to run environments with hundreds or even thousands of machines. Open vSwitch (OVS) is an Open source software switch which can be integrated with SDN control … Continue reading Virtual networking labs – a short introduction to Open vSwitch