Manually moving a Virtual Machine from VMware to OpenShift Virtualization

When it comes to migrating VMs from VMware to OpenShift Virtualization, the Migration Toolkit for Virtualization (MTV) is the easiest option. But what happens if you want to move an unsupported OS over to OpenShift Virtualization? Can this even be done? The short answer is “Yes”, and the longer answer is “It depends on the OS you want to move.”

May 30, 2024

Installing OpenShift using Windows Subsystem for Linux

With interest in OpenShift and more specifically OpenShift Virtualization taking off, users who do not typically use Linux have a need for a Linux workstation in-order to deploy OpenShift. While the oc command used to manage OpenShift does work on Windows other utilities such as the openshift-install command used to deploy OpenShift clusters does not. So whats a Windows using future OpenShift administrator supposed to do?

April 15, 2024

Creating a storage network in OpenShift.

As my usage of OpenShift Virtualization increases, I am finding that I need to create a dedicated network for my storage arrays. For my lab storage I use two Synology devices, both are configured with NFS and iSCSI, and I use these storage types interchangeably. However in the current configuration, all storage traffic (NFS or iSCSI) is routed over two hops, and comes into the server over a 1Gb interface. I would like to change this to work similar to my vSphere lab setup, where all storage traffic goes over my dedicated network “vlan20”, which is not routed, and has a dedicated 10Gb switch.

April 10, 2024

Updating RHCOS Images with Custom Configurations

In the last blog post Dealing with a Lack of Entropy on your OpenShift Cluster we deployed the rng-tools software as a DaemonSet in a cluster. By using a DaemonSet, we took advantage of the tools that Kubernetes gives us for deploying an application to all targeted nodes in a cluster. This worked well for getting the rng daemon up and running on nodes that required it, but not all software will work this way.

March 20, 2024

Dealing with a Lack of Entropy on your OpenShift Cluster

Introduction The Linux Kernel supplies two sources of random numbers, /dev/random and /dev/urandom. Theses character devices can supply random numbers to any application running on your machine. The random numbers supplied by the kernel on these devices come from the Linux kernel’s random-number entropy pool. The random-number entropy pool contains “sufficiently random” numbers meaning they are good for use in things like secure communications. But what happens if the random-number entropy pool runs out of numbers?

October 31, 2023

OpenShift Machine Remediation

Kubernetes and thus OpenShift are designed to host applications in such a way that if a node hosting your application fails, it will reschedule the app on another node automatically, and everything “just keeps working”. This happens without any intervention by an administrator letting you continue on with your life, not getting bothered by some on-call alert system. But what about that node that failed? While the app may be up and running you have a node that is no longer pulling its weight, your cluster capacity is lessened and if you get enough of these failed nodes, other apps may be effected or your cluster may fail.