PowerVM Terminology

VIO Terminology:


VIOS is a special purpose partition that can serve I/O resources to other partitions. The type of LPAR is set at creation. The VIOS LPAR type allows for the creation of virtual server adapters, where a regular AIX/Linux LPAR does not.

VIOS works by owning a physical resource and mapping that physical resource to virtual resources. Client LPARs can connect to the physical resource via these mappings.

VIOS is not a hypervisor, nor is it required for sub-CPU virtualization. VIOS can be used to manage other partitions in some situations when a HMC is not used. This is called IVM (Integrated Virtualization Manager).

HMC - Hardware Management Console. An "appliance" server that is used to manage Power 4, 5, and 6 hardware. The primary purpose is to enable / control the virtualization technologies as well as provide call-home functionality, remote console access, and gather operational data.

SEA - Shared Ethernet Adapter. This is a VIOS mapping of a physical to a virtual Ethernet adapter. With Shared Ethernet Adapters on the Virtual I/O Server logical partition, virtual Ethernet adapters on client logical partitions can send and receive outside network traffic.


A Shared Ethernet Adapter is a Virtual I/O Server component that bridges a physical Ethernet adapter and one or more virtual Ethernet adapters:

The real adapter can be a physical Ethernet adapter, a Link Aggregation or EtherChannel device, or a Logical Host Ethernet Adapter . The real adapter cannot be another Shared Ethernet Adapter or a VLAN pseudo-device.

The virtual Ethernet adapter must be a virtual I/O Ethernet adapter. It cannot be any other type of device or adapter.
 
The two primary methods of providing network redundancy for a VIOC in a dual VIOS configuration are, NIB (Network Interface Backup) and SEA Failover. (These provide protection from the loss of a VIOS or VIOS connectivity to a physical LAN.)

NIB - NIB creates a link aggregation in the client of a single virtual NIC with a backup NIC. (Each virtual NIC is on a separate VLAN and connected to a different VIOS.) This configuration is done in each client OS.

SEA Failover - Shared Ethernet Adapter failover provides redundancy by configuring a backup Shared Ethernet Adapter on a different Virtual I/O Server logical partition that can be used if the primary Shared Ethernet Adapter fails. The network connectivity in the client logical partitions continues without disruption.

Control Channel - Like Heartbeat mechanism in HACMP. will send "Keep Alive" info. Redundancy between VIOS Servers

Link Aggregation or EtherChannel devices - A Link Aggregation, or EtherChannel, device is a network port-aggregation technology that allows several Ethernet adapters to be aggregated. The adapters can then act as a single Ethernet device. Link Aggregation helps provide more throughput over a single IP address than would be possible with a single Ethernet adapter.


For example, ent0 and ent1 can be aggregated to ent3. The system considers these aggregated adapters as one adapter, and all adapters in the Link Aggregation device are given the same hardware address, so they are treated by remote systems as if they are one adapter.

VIOC - Virtual I/O Client. Any LPAR that utilizes VIOS for resources such as disk and network.

VIOS - Virtual I/O Server. The LPAR that owns physical resources and maps them to virtual adapters so VIOC can share those resources.

VEA - Virtual Ethernet adapter. Virtual Ethernet adapters allow client logical partitions to send and receive network traffic without having a physical Ethernet adapter.

VSCSI - Virtual SCSI. Disks are presented to VIOC by creating a mapping between a physical disk or storage pool volume and the vhost adapter that is associated with the VIOC.

Physical adapters with attached disks or optical devices on the Virtual I/O Server logical partition can be shared by one or more client logical partitions. The Virtual I/O Server offers a local storage subsystem that provides standard SCSI-compliant logical unit numbers (LUNs). The Virtual I/O Server can export a pool of heterogeneous physical storage as a homogeneous pool of block storage in the form of SCSI disks.


The following SCSI peripheral-device types are supported:
-> Disks backed up by logical volumes
-> Disks backed up by physical volumes
-> Disks backed up by files
-> Optical devices (DVD-RAM and DVD-ROM)
-> Optical devices backed up by files
-> Tape devices

IVE - Integrated Virtual Ethernet. The capability to provide virtualized Ethernet services to LPARs without the need of VIOS. This functionality was introduced on several Power 6 systems. Some Power 6 systems introduced hardware based network virtualization with the IVE (Integrated Virtual Ethernet) device that allows multiple partitions to share a single Ethernet connection without the use of VIOS.

Promiscuous mode - A port group supports up to 16 logical ports. Thus (depending on MCS value) we could define up to 16 LOGICAL ports and therefore support up to 16 LPARs


To support more than 16 LPARS - we could use multiple HEA if available - or we could assign an Interface to the VIOServer and use it as an SEA (Shared Ethernet Adapter).

A Virtual I/O Server LPAR requires the IVE physical port to be set to promiscuous mode if that port will be used as the physical port in an SEA configuration.

The promiscuous mode option dictates the use of the physical port to one LPAR if set.

MCS value determines the amount of (HEA) resources allocated to a particular Logical HEA port. But in promiscuous mode, we have the entire physical port into one LPAR - thus MCS is not applicable.

HEA - Host Ethernet Adapter. The physical port of the IVE interface on some of the Power 6 systems. A HEA port can be added to a port group and shared amongst LPARs or placed in promiscuous mode and used by a single LPAR (typically a VIOS LPAR).

IVM - Integrated Virtualization Manager. This is a management interface that installs on top of the VIOS software that provides much of the HMC functionality. It can be used instead of a HMC for some systems. It is the only option for virtualization management on the blades as they cannot have HMC connectivity.

NPIV (N Port ID Virtualization) - NPIV can be used in conjunction with the appropriate VIOS version to present a virtualized HBA with a unique WWN directly to a client partition. NPIV (N Port ID Virtualization) capable cards can be used to provide direct connectivity of the client to a virtualized FC adapter. Storage specific multipathing drivers such as PowerPath or HDLM can be used in the client LPAR. NPIV adapters are virtualized using VIOS, and should be used in a dual-VIOS configuration.

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