HP-UX vPars and Integrity VM V6.3 Administrator Guide

enabling access to I/O hardware technology without requiring the support of either vPars or
Integrity VM.
1.4.4.1 Overview of AVIO storage
To provide the flexibility required to meet a variety of data center needs, the vPar or VM storage
subsystem consists of three storage architectures - shared I/O, attached I/O, and NPIV For more
information about shared I/O, attached I/O and NPIV, see Chapter 6 (page 63) and Chapter 7
(page 101).
1.4.4.1.1 Shared I/O
The shared I/O architecture is a means by which a vPar and VM guest accesses an entirely
virtualized storage subsystem provided by vPars and Integrity VM. The vPar and VM guest storage
subsystem emulates real hardware to the vPar and VM guest while interacting with the VSP to
complete the vPar or VM I/O operation to the VSP storage entity. This abstraction provides the
ability of a VSP administrator to share physical VSP storage hardware across multiple VMs and
to allocate that storage at sub-LUN levels.
The individual storage LUNs are shared by dividing a VSP LUN into smaller parts, such as logical
volumes, or files. Each of these sub-LUN VSP entities can then be used as a media for separate
virtual storage devices. The vPars and VM guests access the virtual storage devices as real storage
devices, with no knowledge that the virtual storage media is actually a sub-LUN VSP entity.
The way the virtual storage media is accessed by the vPar or VM guest storage subsystem allows
vPars or VM guests to share physical VSP storage adapters. All vPar and VM guest I/O requests
in shared I/O are processed by virtual adapters. A virtual adapter is an emulation of a proprietary
adapter that a special driver loaded into the guest OS accesses as a real device.
1.4.4.1.2 Attached I/O
Attached I/O allows a vPar or VM guest visibility to the real device and its properties. In this
architecture, the vPar or VM guest storage subsystem attaches a path to a LUN on the VSP to a
virtualized storage adapter. The LUN can be a tape, media changer, or burner.
The main difference between shared I/O and attached I/O is the degree to which a physical
storage subsystem is virtualized. In attached I/O, only the storage adapter is virtualized. Therefore,
only the VSP physical storage adapters might be shared.
1.4.4.1.3 NPIV devices
NPIV is a fibre channel technology that allows you to create multiple virtual Fibre Channel ports
over a single physical port on the VSP. These are then assigned to vPars or VM guests on the VSP.
With NPIV, a vPar or VM guest discovers SAN devices on its own, just the way it is done on a
physical server. The vPar or VM guest views the real targets and devices to which the VSP does
not have any visibility. For more information about NPIV and the steps to configure NPIV, see
Chapter 7 (page 101).
1.4.4.2 AVIO-Networking
AVIO networking feature provides the facility for a vPar or VM guest to communicate with other
guests, VSP, and with the outside world through a shared NIC. The shared NIC could be a physical
NIC or an APA interface.
Before configuring the guest or virtual LAN interface, a vswitch must be created over a physical
NIC. Guests can then be associated with one or more vswitches. The guests are assigned vNICs
on these vswitches and these vNICs can be configured like a physical NIC on the host. The vswitch
allows configuring VLANs on individual ports thus creating multiple subnets on the same vswitch.
A vswitch can also be created without any physical NIC associated with it. Guests associated with
such a switch can communicate with each other but not with the VSP or outside the VSP.
For more information about using AVIO networking, see Chapter 8 (page 111).
1.4 vPars and Integrity VM V6 architecture 21