Advanced POWER Virtualization on IBM System p5 - Previous ...

For more information about System p5 systems RAS, refer to the whitepaper IBM
System p5: a Highly Available Design for Business-Critical Applications, available
at:
http://www.ibm.com/servers/eserver/pseries/library/wp_lit.html
For information about service and productivity tools for Linux on <strong>POWER</strong>, refer
to:
http://techsupport.services.ibm.com/server/lopdiags
1.2.2 Availability and serviceability in virtualized environments
In partitioned environments where more business-critical applications are
consolidated on different operating systems with the same hardware, additional
availability and serviceability is needed to ensure a smooth recovery of single
failures and allow most of the applications to still be operative when one of the
operating systems is out of service. Furthermore, high availability functions at the
operating system and application levels are required to allow for quick recovery
of service for the end users.
In the System p5 systems, there are several mechanisms that increase overall
system and application availability by combining hardware, system design, and
clustering.
Dynamic processor deallocation and sparing
The <strong>POWER</strong> Hypervisor will deallocate failing processors and replace them with
processors from unused CUoD capacity, if available.
Memory sparing
If, during power-on, the service processor identifies faulty memory in a server
that includes CUoD memory, the <strong>POWER</strong> Hypervisor will replace the memory
with unused memory in the CUoD pool. If there is no spare memory, the <strong>POWER</strong>
Hypervisor will reduce the capacity of one or more partitions. On the IBM System
p5 Models 590 and 595, memory sparing will substitute unused CUoD memory
for all general memory card failures. On the IBM System p5 Model 570, memory
sparing will substitute CUoD memory for up to one memory card failure.
Check with your IBM representative for the availability of this function on IBM
System p5 servers.
Chapter 1. Introduction 7