Andy Hartman
Sr. Systems Engineer
IBM has released a version of KVM (Kernel based Virtual Machine) to run on IBM z Systems. This will allow for three different virtualization technologies to host Linux servers on IBM EC/BC12’s and z13’s. PR/SM (single Linux image in an LPAR) and z/VM have been around for a long time with z/VM bringing the most capabilities and advantages to running Linux on z Systems. KVM brings a different type of virtualization based on using Linux as the host operating system similar to KVM on Intel and other hardware architectures.
KVM for z Systems allows KVM administrators on Intel and other platforms to utilize their existing skills to deploy and manage Linux images on z Systems in the same way they do on their other platforms. KVM also enables Linux images to be deployed and managed by OpenStack software such as IBM Cloud Manager with OpenStack and other solutions. KVM for z Systems is meant to be deployed in new environments that don’t have z/VM as well as along side z/VM in environments that currently utilize z/VM to exploit System z hardware features to enhance Linux workloads. KVM is not meant to replace existing z/VM environments.
For existing z/VM administrators, KVM for z Systems will be quite different from how they manage Linux guests under z/VM today. KVM utilizes a single Linux server running inside an LPAR hosting multiple Linux guests. The management of these guests are accomplished through Linux commands and other software running on this Linux KVM host as well as OpenStack solutions running on other platforms. KVM for z Systems is built on a newer version of Linux, which means that there are significant changes to how you manage this Linux host, from new commands to different system initialization mechanisms etc. If your familiar with SLES 12 or RHEL 7, you’ve already made the transition to the newer Linux versions.
Storage configurations in KVM are managed by the KVM host with a lot of different options and capabilities for managing both DASD and LUNs. This will impact the choices made for backup and recovery as well as the planning for disaster recovery. Some of these features include capabilities such as thin provisioning and snapshots from within the KVM host to support it’s Linux guests. Networking to support underlying Linux guests have many capabilities such as bonding and virtual switches etc. The various options will be familiar to KVM administrators on other platforms making implementation straight forward. Planning at the OSA level will need to be done to ensure proper redundancy and fail over capabilities. KVM for z Systems comes with all the familiar security features and capabilities that you would expect on a Linux operating system including SELinux, logging and audit capabilities. IBM has included Hypervisor Performance Manager which can be used to balance performance of many Linux guests within a single KVM LPAR based on workload policies.
The configuration of the hosted Linux guests on the KVM host is done with XML files or upstream OpenStack and other Cloud management software. IBM has made many of the KVM for z System components available as open source and these have been included in the most recent version of OpenStack, allowing you to manage to this environment if you have this version (KILO) of OpenStack.
It will be interesting as KVM on z Systems matures, and we see more information on performance and other changes such as supporting additional hosted Linux distributions, to see how this technology is adopted by organizations looking to consolidate workloads and build cloud solutions. If you have questions about KVM for z Systems please contact you Mainline Account Executive to discuss this new virtualization choice for Linux on System z.