Live Partition Migration (LPM) is a PowerVM feature using which VMs running OS like AIX, IBMi, or Linux can be migrated from one Power Server to another with zero down time. During LPM, CPU state, memory contents, Network connections, virtual devices are transferred live from the source server to the target server.  

The migration process consists of two key stages: 

LPM Validation – Ensures both systems meet all requirements. 

LPM Execution – Performs the actual live migration. 

For NPIV-backed client disks, LPM historically supported two types of validation: 

Before this enhancement, both required that the exact same storage target ports to be visible from source and target VIOS. 

In real-world customer environments, infrastructure modernization often introduces temporary or permanent SAN topology differences such as  

New SAN switches installed, Old fabrics decommissioned, New Power servers added to different SAN networks, or Storage arrays reachable through different target ports, but the same LUN IDs. 

In such cases: 

LUNs are identical but Target ports differ 

LPM validation fails in such cases because the legacy validation logic insists on matching target storage port WWPNs. 

This becomes problematic when new switches cannot be connected to the older fabric due to various reasons such as Firmware or vendor interoperability issues prevent merging fabrics, different speeds (8G/16G/32G) or zoning policies exist, or the Customers want a phased migration path, etc.  

Below is the conceptual scenario: 

Source Server → Fabric-A → Storage (Port-1) 

Target Server → Fabric-B → Storage (Port-2)  

LUNs are the same, Target ports differ and the validation fails.  

Despite the storage being correctly reachable, LPM rejects the migration because the storage port WWPNs don’t match. 

To address this gap, this LPM enhancement introduces a new validation option: 

LUN-Only Validation (Skip Port Validation) 

This allows LPM to succeed when: 

This enhancement is supported from VIOS 4.1.2.0 onwards. 

NOTE: This is supported for IBMi and Linux OS only. AIX will be supported in future releases. Also, HMC GUI changes are planned for 2026 HMC releases.  

What changes? 

This update enables LPM workflows in modernization scenarios that were previously blocked. 

A new attribute, port_val, is introduced on the vioslpm0 device in VIOS. 

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