Earlier last year, IBM announced that it was withdrawing its KVM for IBM z product, and instead continue to support and develop this technology as open source. Two of the three supported IBM on z Linux distribution providers, SuSE (SLES) and Canonical (Ubuntu), have put this support in their current IBM z distributions. Red Hat appears to be working to support this in a future release, probably RHEL 7.5.
KVM (Kernel-based Virtual Machine) is used extensively on other platforms for virtual machine hosting. It is a technology familiar to many system administrators, and can be easily integrated into their existing environments, without a steep learning curve.
Implementing KVM on either SuSE or Ubuntu is very easy on IBM z. Installation of either SLES or Ubuntu, into and LPAR to act as a KVM host, is straight forward and can be accomplished in a short time, similar to installing a Linux image on any other architecture. Both distributions make it easy to install the needed packages for running KVM. Both distributions have preconfigured patterns to allow for creating a KVM host during initial installation, as well as making it easy to add this functionality after initial installation.
Creating virtual machines under KVM is even simpler and takes minutes to complete. The steps are identical to other platforms, such as x86. Management of the virtual machines is also very easy through command line, or a gui interface utilizing KVM itself, as well as other tools and deployment managers that use api’s to communicate with KVM to carry out their tasks.
KVM utilizes XML for its virtual machine definition files, which allows for easy configuration and modification. These XML files can be edited directly with an editor of your choice. There are also command line tools that can help with this, such as virt-xml, which allows you to edit the whole file or specific parts of the file, or add or remove specific components within the file, such as a disk device, network device, etc.
The command line interface used by KVM is virsh. This command can be used as a single execution command, say to query the status of a virtual machine, or it can be utilized as an execution environment that can be used to submit multiple commands within a virsh session. There are several other commands that are used for KVM, such as virt-install for installing virtual machines, virt-clone for cloning existing virtual machines, virt-viewer to access the virtual machine graphical console of the virtual machine, and virt-top to display resource usage of virtual machines on this KVM host.
KVM uses virt-manager for its gui interface. While using this tool, you can create new virtual machines, manage and move them from one KVM host to another, as well as manage other KVM hosts remotely.
Documentation for setting up KVM on either SLES or Ubuntu can be found at each vendor’s site, and both provide detailed examples and explanations on KVM from setup to deployment of virtual machines. They also have documentation on converting from IBM’s KVM product to their KVM environment.
Utilizing KVM, along with other technologies like Dynamic Partition Manager, on IBM z can make for a very easy-to-configure environment that can respond to dynamic changes in real time, as well as allow non-mainframe centric administrators the ability to easily manage IBM z environments.
Mainline has extensive experience with IBM z and it’s many virtualization technologies. Please contact your Mainline Account Executive to answer any questions you may have, or to set up a more in-depth discussion about what you can do with KVM or other virtualization capabilities that IBM z has to offer.
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