iCan Blog Archive

Last year, IBM provided support to suspend an i partition, which I previously wrote about in “Suspend my i”. 

IBM i 7.1 TR4 added Live Partition Mobility. With Live Partition Mobility, you can take an active, running IBM i partition and move it from one frame to another frame, without disruption to your applications.

There are both hardware and software prerequisites:

  • POWER7 tower/rack system for both the source and destination systems
    • Firmware service pack 730_xx, 740_xx, or later
    • IBM Hardware Management Console V7R7.5.0M0, or later
  • All I/O must be virtual and supported by VIOS; it can be Virtual SCSI (VSCSI), Virtual Fibre Channel (NPIV) or Virtual Ethernet
  • The configuration must use only external storage and that storage must be accessible to both the source and destination systems
  • Both source and destination systems must be on the same Ethernet network
  • IBM i 7.1 TR4 PTF group – SF99707 level 4
  • PowerVM Enterprise Edition on both the source and target system
  • VIOS or later on both the source and target system

There are a few restrictions that are too detailed to review in this blog; the Live Partition Mobility documentation in the IBM I Technology Updates site reviews the complete set of prerequisites, requirements and restrictions.

The actual move of a partition is initiated from the HMC, or using PowerVC (PowerVC calls this function ‘hot migration’).

In general, applications and the operating system are unaware that the partition is moved from one system to another. There are some exceptions to this, such as Collection Services; when the partition is starting to run on the target system, the Collection Services collector job will cycle the collection so correct hardware information is recorded on the target system.

There are two new work management exit points that are part of the IBM i suspend and mobility support. These exit points allow to you run a program before and after a partition is suspended or moved. (These exit points are the same, regardless of whether you are suspending a partition or moving a partition). 

                   Work with Registration Information     
Type options, press Enter.                                   
  5=Display exit point   8=Work with exit programs           
     Exit                  Point                                           
Opt  Point                 Format    Registered  Text                    
_    QIBM_QWC_RESUME       RSMS0100     *YES     Resume system
_    QIBM_QWC_SUSPEND      SSPS0100     *YES     Suspend system          

The suspend exit is called before the partition is suspended or moved and is called twice. The first time it is called to check to see if the operation is allowed. The second call is to prepare for the move or suspend operation.

The resume exit is called after the move is complete or after the system has been restarted from a suspended state. Applications can use these exit points to monitor and accept or refuse move or suspend requests. Running an exit program after a move or suspend also allows an application to refresh any copies of any system-specific information, log information about mobility requests for licensing or other purposes, adjust heart beat rates or whatever actions an application may require.

The following messages may be logged to the QSYSOPR message queue as part of the suspend or move request:

  • CPI09A5 – Partition suspend request in progress.
  • CPI09A6 – Partition not ready for suspend request.
  • CPI09A7 – Partition suspend request canceled.
  • CPI09A8 – Partition resumed after migration.
  • CPI09A9 – Partition resumed from hibernation.

The system serial number will change when a partition has been moved. The model and processor feature may also change.

Documentation on enhancements added to IBM i via TRs is documented on the Technology Refreshes site.

Other sources for documentation on Live Partition Mobility for IBM i include:

This blog post was edited to fix broken links on February 18, 2020.

This blog post was originally published on IBMSystemsMag.com and is reproduced here by permission of IBM Systems Media.