Pre migration checklist

Skill development for s390x architecture

Ensure that the team has the necessary expertise in s390x systems. This includes understanding platform-specific configurations, software availability, performance tuning, and troubleshooting.

Ecosystem assessment

Conduct a thorough review of the existing infrastructure:

• Identify all servers involved in the migration.
• Determine appropriate sizing for CPU, memory, and disk resources.
• Validate network requirements to ensure compatibility and performance.

OSA adapter configuration

Verify whether OSA (Open Systems Adapter) network adapters can operate in promiscuous mode or not. This affects the way how the adapter is configured and used. Shared OSA adapters can be configured only on one LPAR in promiscuous mode.

If OSA adapters are not run in promiscuous mode, the MAC address of the adapter in the VM must be registered manually on the OSA adapter. This manual step can be prevented by configuring the learning mode on the adapter, so the MAC address is registered automatically during the first connection to the VM. After a configurable time when no access happens to the VM, the MAC address is removed and must be relearned during the next connection.

Storage considerations

For production environments, Red Hat OpenShift Data Foundation is recommended for managing storage in the cluster. This method is fast and supports migration of VMs within the cluster out of the box. Using local storage means attaching disks directly to the compute node, which prevents migration of VM.