Debugging Memory Issues with Open vSwitch DPDK

Debugging Memory Issues with Open vSwitch DPDK


This article is about debugging out-of-memory issues with Open vSwitch with the Data Plane Development Kit (OvS-DPDK). It explains the situations in which you can run out of memory when using OvS-DPDK and it shows the log entries that are produced in those circumstances. It also shows some other log entries and commands for further debugging.

When you finish reading this article, you will be able to identify that you have an out-of-memory issue and you’ll know how to fix it. Spoiler: Usually having some more memory on the relevant NUMA node works. It is based on OvS 2.9.

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Red Hat Container Development Kit (CDK) With Nested KVM

Red Hat Container Development Kit (CDK) With Nested KVM


If you are like me, you probably prefer to install new and exploratory software in a fresh virtual machine (VM) or container to insulate your laptop/desktop from software pollution (TM). Red Hat Container Development Kit (CDK) relies on virtualization to create a Red Hat Enterprise Linux (RHEL) virtual machine to run OpenShift (based on Kubernetes). Red Hat specifically supports installation of the CDK on Windows, macOS, and RHEL Server, but if you are running Fedora, RHEL Workstation, or even CentOS, you will run into trouble. If you are not running a supported desktop, you can always use a RHEL Server virtual machine, and this tutorial is for you.

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Setting up KVM on Red Hat Enterprise Linux

Editor’s Note:  If you have a Linux system that runs KVM and would like to try Red Hat Enterprise Linux on KVM, follow our KVM Get started guide,

The kernel-based Virtual Machine (KVM) is a virtualization infrastructure many have become familiar with throughout the industry. This article will guide you through getting a basic KVM hypervisor up and running and ready for use. In order to fully utilize the KVM, you will need a CPU that has virtualization extensions, and these will need to be enabled in the BIOS of the machine you’re working on. In general, you’ll need to look to enable VT-X or AMD-V depending on your system architecture.

Our Objectives

  • Set up a RedHat Enterprise Linux (RHEL 7.2) server
  • Identify whether Virtualisation extensions are present
  • Install KVM and associated software components
  • Networking Considerations
  • Configure VNC
  • Demonstrate how to fire up a new Virtual Machine running on the KVM hypervisor
  • Listing existing Virtual Machines

Installing RHEL

For the purposes of this article, I’m going to be showing you how to manually install KVM from the command line, rather than opt to have it installed as part of the RHEL installation process. This will allow us to fine tune the installation by only installing what we need, and it also gives us a better understanding of how everything fits together. With this in mind, we will be working on the basis that you have opted for a ‘minimal install’ of RHEL. After first boot, you will want to register to the Red Hat network to receive updates and download software. This can be done by running the following command:

subscription-manager register –auto-attach

You will be prompted to enter your username and password.

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