Virtual I/O Server Overview

What is Advanced POWER Virtualization (APV)

APV – the hardware feature code for POWER5 servers that enables:
– Micro-partitioning – fractional CPU entitlements from a shared pool of
processors, beginning at one-tenth of a CPU
– Partition Load Manager (PLM) – a policy-based, dynamic CPU and
memory reallocation tool
– Physical disks can be shared as virtual disks to client partitions
– Shared Ethernet Adapter (SEA) – A physical adapter or EtherChannel in
a VIO Server can be shared by client partitions. Clients use virtual
Ethernet adapters

Virtual Ethernet – a LPAR-to-LPAR Virtual LAN within a POWER5 Server
– Does not require the APV feature code


Why Virtual I/O Server?

POWER5 systems will support more partitions than physical I/O slots
available
– Each partition still requires a boot disk and network connection, but
now they can be virtual instead of physical

VIO Server allows partitions to share disk and network adapter resources
– The Fibre Channel or SCSI controllers in the VIO Server can be
accessed using Virtual SCSI controllers in the clients
– A Shared Ethernet Adapter in the VIO Server can be a layer 2 bridge
for virtual Ethernet adapters in the clients

The VIO Server further enables on demand computing and server
consolidation



Virtualizing I/O saves:
– Gbit Ethernet Adapters
– 2 Gbit Fibre Channel Adapters
– PCI slots
– Eventually, IO drawers
– Server frames?
– Floor space?
– Electric, HVAC?
– Ethernet switch ports
– Fibre channel switch ports
– Logistics, scheduling, delays of physical Ethernet, SAN attach

Some servers run 90% utilization all the time – everyone knows which
ones.

Average utilization in the UNIX server farm is closer to 25%. They don’t
all maximize their use of dedicated I/O devices

VIO is departure from “new project, new chassis” mindset


Virtual I/O Server Characteristics


Requires AIX 5.3 and POWER5 hardware with APV feature

Installed as a special purpose, AIX-based logical partition

Uses a subset of the AIX Logical Volume Manager and attaches
to traditional storage subsystems

Inter-partition communication (client-server model) provided via
the POWER Hypervisor

Clients “see” virtual disks as traditional AIX SCSI hdisks, although
they may be a physical disk or logical volume on the VIO Server

One physical disk on a VIO server can provide logical volumes for
several client partitions


Virtual Ethernet

Virtual Ethernet
– Enable inter-lpar communications without a physical adapter
– IEEE-compliant Ethernet programming model
– Implemented through inter-partition, in-memory communication

VLAN splits up groups of network users on a physical network onto
segments of logical networks

Virtual switch provides support for multiple (up to 4K) VLANs
– Each partition can connect to multiple networks, through one or more adapters
– VIO server can add VLAN ID tag to the Ethernet frame as appropriate.
Ethernet switch restricts frames to ports that are authorized to receive frames
with specific VLAN ID

Virtual network can connect to physical network through “routing"
partitions – generally not recommended


Why Multiple VIO Servers?

Second VIO Server adds extra protection to client LPARS

Allows two teams to learn VIO setup on single system

Having Multiple VIO Servers will:
– Provide you Multiple paths to your OS/Data Virtual disks
– Provide you Multiple paths to your network

Advantages:
– Highest superior availability to other virtual I/O solutions
– Allows VIO Server updates without shutting down client LPAR’s