Transitioning IBM i LPARs from Dual VIOS to Single VIOS

Overview

When transitioning an IBM i Logical Partition (LPAR) from a Dual Virtual I/O Server (VIOS) region to a Single VIOS region or Single VIOS Power Hosting Node in Skytap. Users may encounter non-reporting disk resources in Service Tool(SST) which is related to multi-path configurations even though the configured disks are present in the virtual machine. This KB provides guidance in managing these configurations to ensure a smooth transition and optimized system performance.

Please perform the below on your IBM i VM after transitioning from a Dual VIOS host to a Single VIOS host.

Removing Failed or Non-Reporting hardware resources

• Login to your IBM i VM as a Security Officer.
• Access System Service Tools (SST) using the STRSST command.
• Log in with the appropriate SST credentials.
• Navigate through the following options
  Option 1: Start a service tool
  Option 7: Hardware service manager
  Option 4: Failed and non-reporting hardware resources
  Remove any resources listed as DMPxxx or DDxxx with an unknown status by selecting Option 4=Remove.
• Exit SST by pressing F3 three times and then Enter.

Resetting the Multipathing Configuration

Use the Advanced Analysis command MULTIPATHRESETTER -CONFIRM -ALL to align the expected number of paths with the currently reporting paths

• Log in to your IBM i VM as a Security Officer
• Access System Service Tools (SST) using the STRSST command
• Log in with the appropriate SST credentials.
• Navigate through the following options:
  Option 1: Start a service tool and press Enter.
  Option 4: Display/Alter/Dump and press Enter.
  Option 1: Display/Alter storage and press Enter.
  Option 2: Licensed Internal Code (LIC) data and press Enter.
  Option 14: Advanced analysis and press Enter.
• At the Select Advanced Analysis Command screen, scroll down, type 1 by MULTIPATHRESETTER, and press Enter.
• At the Specify Advanced Analysis Options screen, type -CONFIRM -ALL and press Enter.
• Follow the on-screen instructions to confirm that the paths should be reset.

This procedure ensures that the system's multi-path configuration is optimized by removing unnecessary paths, thereby improving system reliability.