IBM eServer OpenPower 720, Technical Overview And Introduction

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OpenPower 720 Technical Overview and Introduction
physical processor. A maximum of 10 micro-partitions for each physical processor can be
defined, but on a loaded system the practical limit is less.
Partitions using Micro-Partitioning technology can also be defined with the capped and
uncapped attributes. A capped micro-partition is not allowed to exceed the defined share,
while an uncapped partition is allowed to consume additional capacity with fewer restrictions.
Uncapped partitions can be configured to the total idle capacity of the server or a percentage
of it. Configuration through the HMC menus sets the allowed share and the capped or
uncapped attribute.
The POWER5 processor-based systems use the POWER Hypervisor, which is the new active
Hypervisor to execute Micro-Partitioning technology. The Hypervisor of existing POWER4
processor-based systems is working on a demand basis, as the result of machine interrupts
and callbacks to the operating system.
The Virtual I/O Server described in 2.9, “Advanced OpenPower Virtualization” on page 34,
builds on all the POWER5 and POWER Hypervisor enhancements to reach the highest level
of granularity of installed system resources.
Figure 2-12 shows the Micro-Partitioning technology and LPAR concepts.
Figure 2-12 LPARs using Micro-Partitioning technology
Virtual I/O Server
The Virtual I/O Server is a special purpose partition to provide virtual I/O resources to client
partitions. It is available as software (5724-K81) and requires an HMC for installation and
configuration. The Virtual I/O server owns the real resources that will be shared with the other
clients. The Virtual I/O technology allows a physical adapter assigned to a partition to be
shared by one or more partitions, enabling clients to minimize their number of physical
adapters. Virtual I/O will be used to reduce costs by eliminating the requirement that each
partition has a dedicated network adapter, disk adapter, and disk drive.
It is preferred that you use the Virtual I/O server in a partition with dedicated resources to help
ensure stable performance.
The two major functions that are provided from the Virtual I/O Server are described in the
following sections.
Virtual I/O
Server
Virtual
adapter
Virtual
SCSI
AIX
v5.2
AIX
v5.3
Li
n
ux
Li
n
ux
AI
X v
5
.3
AI
X v
5
.3
POWER Hypervisor
Virtual Ethernet
I/O
Storage Network
I/O
Sto Net
I/O
Sto Net
I/O
Sto Net
HMC
1 CPU 1 CPU 1 CPU 1 CPU
I/O
S N
Network
External
storage
Micro-Partitioning
POWER5 Partitioning