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IBM Power 750 and 760 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 specific storage devices that are supported for Virtual I/O Server,
see the following web page:
http://www14.software.ibm.com/webapp/set2/sas/f/vios/documentation/datasheet.html
N_Port ID Virtualization
N_Port ID Virtualization (NPIV) is a technology that allows multiple logical partitions to access
independent physical storage through the same physical Fibre Channel adapter. This adapter
is attached to a Virtual I/O Server partition that acts only as a pass-through, managing the
data transfer through the POWER Hypervisor.
Each partition that uses NPIV is identified by a pair of unique worldwide port names, enabling
you to connect each partition to independent physical storage on a SAN. Unlike virtual SCSI,
only the client partitions see the disk.
For additional information and requirements for NPIV, see the following resources:
PowerVM Migration from Physical to Virtual Storage, SG24-7825
IBM PowerVM Virtualization Managing and Monitoring, SG24-7590
Client Partition 1
Client Partition 2
I/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