A new HMC & Firmware 840 feature allows LPM in a dual VIOS configuration when one VIOS is failed. Previously, LPM was not allowed if one of the source VIOS (in a dual VIOS configuration) was in a failed state. Both VIOSes had to be operational to perform LPM. The new support allows the HMC to cache adapter configuration from both VIOSes. Whenever changes are made to the configuration, the cached information will be updated on the HMC. If one VIOS is failed, instead of querying the failed VIOS, the HMC cache is used instead to create the new configuration on the target VIOS. This support was needed to cover the situation where there’s failed hardware which is causing an outage on the VIOS and requires a disruptive repair action. This new feature is enabled using a server wide HMC setting to enable the automatic caching of VIOS configuration details.
You can enable/disable this setting using the new Enhanced+ HMC interface. You’ll find it under General Properties of the Managed System (Server).
You can also enabled/disable this feature using the HMC command line, with migrlpar.
$ migrlpar -o set -m <managed system> -r sys -i “allow_inactive_source_storage_vios=1/0”
$ lslparmigr -r sys -m <managed system> -F allow_inactive_source_storage_vios
Whilst we’re on the subject of new HMC features; you may have heard that it is now possible to disable LPM on a per partition basis. You read more about this feature here:
This feature can be enabled/disabled, per partition, using the HMC Enhanced+ interface. You’ll find this under General Properties of a Partition.
You can also use the HMC command, chsyscfg, to toggle this setting.
$ chsyscfg -r lpar -m Server-8286-42A-SN991F99V -i "name=RHEL_6_5,migration_disabled=1"
$ lssyscfg -r lpar -m Server-8286-42A-SN991F99V -F name,migration_disabled
Useful links and additional information.
Live Partition Mobility (LPM) improvements in PowerVM 2.2.4
HMC V8 R8.4.0 Command Line specification
HMC Manual Reference Pages - MIGRLPAR (1)
IBM Power Systems HMC Implementation and Usage Guide
Hardware Management Console - Related technical information