Manual installation of Linux on Z is often time-consuming and requires a deep knowledge of Z systems. Developers that don’t have sufficient experience with Z systems, can run into issues – anything from minor mistakes to huge errors. Most available tools only provide a specific image or have configuration limitations that do not use full Z potential. Currently, there is no other solution that provides support for all three hypervisors on Z natively.

Tessia, an open source project for Z resource management and automated installation of Linux distribution, manages relationships between Z datacenter resources and allocates them to specific projects and users according to a role-based schema. Using these resources, Tessia can deploy Linux distribution from a repository, such as a mounted ISO image obtained from distribution partner. It uses HMC API to control LPARs, 3270 terminal for z/VM and ssh for KVM-based installations. A distro is installed with “automatic installation” mode, tessia provides customizable templates to fine-tune installation process. In addition, Tessia supports running Ansible playbooks on installed machines and all are scheduled internally to avoid resource conflicts.

Tessia can be included into existing pipelines and be part of continuous release process. It enables developers to effortlessly bring up their environments or try out new releases before migration. Tessia can work even with pre-release distributions and drive faster release cycles and adoption of new technologies. Overall, it improves experience with Linux on Z, which in turn facilitates faster adoption of open source on Z platform.

Unique features of Tessia include:

• Supports a variety of hardware options – such as Z features and Linux on Z distributions on LPAR, z/VM guests and KVM guests, supporting a variety of hardware options.
• Designed with “service” in mind – let’s both end-users bring up a system in desired configuration and included in a CI/CD workflow through use of REST API and command-line interfaces.
• Provides rich customization abilities with Ansible playbooks and installation templates for Red Hat Enterprise Linux, SUSE Linux Enterprise Server and Ubuntu distributions.
• Helps system administrators allocate resources per user and project, minimizing risks of resource conflicts.

Tessia has been actively used by testers and developers in CI environments in IBM for Linux-related activites. For more information, watch this Tessia introductory video or review these Tessia slides from Open Mainframe Summit 2020.