Managing a virtual infrastructure by code makes the daily work of an administrator much easier. Especially when it comes to providing test environments, such as cluster servers, which may need to be often completely torn down and reinstalled. Under Linux, KVM (Kernel Virtual Machine) and libvirt is a standard for
Continue readingCategory: Linux
Quick Start KVM libvirt VMs with Terraform and Ansible – Part 2
In the first part of my Quickstart Guide, I showed how to use Terraform Script to start new VMs or guests under KVM libvirt very flexibly and quickly. Once the virtual machines are up and running, Ansible can be used to configure them and install additional software. Ansible is an
Continue readingQNAP serial console setup with Arduino
Yesterday I had to repair a wildly blinking QNAP NAS TS-212 that could not be accessed via HTTP Web UI or SSH. Also the system rebooted regularly and it was not clear why … Also googling didn’t get me anywhere, except wild speculations in all possible directions. Hmm… in a
Continue readingXEN: How to remove an old-school EXT3 Storage Repository and create a local LVM based SR with RAID 1
With newer XenServer Version (> 5.x) you cannot longer use the old EXT3 based local storage repositories to store your virtual disks. Citrix has introduced LVM based storage repositories instead. Caution: Make a backup before executing the following steps, otherwise you’ll lose all your data on the disk! I assume,
Continue readingDocker Swarm Cluster on Raspberry Pi with Raspbian Stretch
Docker is is on everyone’s lips and now you can also use Docker on the Raspi. But one is not enough, we’ll install a Docker Swarm Cluster. If you’d like to know more about Docker and Swarm see the homepage of Docker Community. First install a fresh Rasbian Stretch image
Continue readingBasic setup of a Multi Node Apache Kafka/Zookeeper Cluster
Prerequesites Install three nodes with CentOS 7 with at least 20GB Disk, 2 GB RAM and two CPU Cores. Install JDK yum install -y java-1.8.0-openjdkl java-1.8.0-openjdk-devel net-tools Set JAVA_HOME in ~/.bashrc # Set Java-Home export JAVA_HOME=”/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.151-5.b12.el7_4.x86_64/jre” export PATH=$JAVA_HOME/bin:$PATH Disable SELinux, Firewall and IPv6 systemctl disable firewalld systemctl stop firewalld echo
Continue reading