Specifications

140 IBM Power 770 and 780 Technical Overview and Introduction
Figure 3-12 shows an example where one physical disk is divided into two logical volumes by
the Virtual I/O Server. Each client partition is assigned one logical volume, which is then
accessed through a virtual I/O adapter (VSCSI Client Adapter). Inside the partition, the disk is
seen as a normal hdisk.
Figure 3-12 Architectural view of virtual SCSI
At the time of writing, virtual SCSI supports Fibre Channel, parallel SCSI, iSCSI, SAS, SCSI
RAID devices, and optical devices, including DVD-RAM and DVD-ROM. Other protocols such
as SSA and tape devices are not supported.
For more information about the specific storage devices supported for Virtual I/O Server, see:
http://www14.software.ibm.com/webapp/set2/sas/f/vios/documentation/datasheet.html
Virtual I/O Server functions
The Virtual I/O Server has a number of features, including monitoring solutions:
򐂰 Support for Live Partition Mobility starting on POWER6 processor-based systems with the
PowerVM Enterprise Edition. For more information about Live Partition Mobility, see 3.4.5,
“PowerVM Live Partition Mobility” on page 141.
򐂰 Support for virtual SCSI devices backed by a file, which are then accessed as standard
SCSI-compliant LUNs.
򐂰 Support for virtual Fibre Channel devices that are used with the NPIV feature.
򐂰 Virtual I/O Server Expansion Pack with additional security functions such as Kerberos
(Network Authentication Service for users and client and server applications), Simple
Network Management Protocol (SNMP) v3, and Lightweight Directory Access Protocol
(LDAP) client functionality.
򐂰 System Planning Tool (SPT) and Workload Estimator, which are designed to ease the
deployment of a virtualized infrastructure. For more information about the System
Planning Tool, see 3.5, “System Planning Tool” on page 150.
Client Partition 1 Client Partition 2I/O Server Partition
POWER Hypervisor
LVM
Physical
Adapter
Hdisk Hdisk
Logical
Volume 1
Logical
Volume 2
VSCSI
Server
Adapter
VSCSI
Client
Adapter
VSCSI
Client
Adapter
Physical Disk
(SCSI, FC)
VSCSI
Server
Adapter