Consideration for AMS ( Active Memory Sharing ) with LPM ( Live Partition Mobility)

This techdnote will focus on the requirement for the shared memory pool paging devices that are critical when migrating a shared memory partition to another Managed system.

The requirement is as follows:

"Paging space devices can only be assigned to one shared memory pool at a time.
You cannot assign the same paging space device to a shared memory pool on one
system and to another shared memory pool on another system at the same time. "

Here is an illustration of the importance of having this requirement in the documentation.

If you erroneously assigned a set of paging devices in the SAN
(that could be accessed by all the VIOS partitions in the source and destination servers)
to the shared memory pool in the source server and the shared memory pool in the
destination server.

This will result in memory corruption when data is read from the paging devices
during a migration operation or subsequent memory access post-migration.


References:
===========
Infocenter topic:
Verifying that the destination shared memory pool contains an available paging space device
http://publib.boulder.ibm.com/infocenter/powersys/v3r1m5/index.jsp?topic=/iphc3/iphc3hmcpreppsd.htm

http://www.redbooks.ibm.com/redpapers/abstracts/redp4470.html
( Under Section: Creating the shared memory pool )