Virtual Scsi; Virtual Ethernet - IBM Power Systems E870 Technical Overview And Introduction

Draft Document for Review October 14, 2014 10:19 am

3.1.1 Virtual SCSI

The POWER Hypervisor provides a virtual SCSI mechanism for the virtualization of storage
devices. The storage virtualization is accomplished by using two paired adapters:
A virtual SCSI server adapter
A virtual SCSI client adapter
A Virtual I/O Server (VIOS) partition or an IBM i partition can define virtual SCSI server
adapters. Other partitions are
which is described in 3.4.4, "Virtual I/O Server" on page 123. The VIOS software is included
on all PowerVM editions. When using the PowerVM Standard Edition and PowerVM
Enterprise Edition, dual VIOSes can be deployed to provide maximum availability for client
partitions when performing VIOS maintenance.

3.1.2 Virtual Ethernet

The POWER Hypervisor provides a virtual Ethernet switch function that allows partitions on
the same server to use fast and secure communication without any need for physical
interconnection. The virtual Ethernet allows a transmission speed up to 20 Gbps, depending
on the maximum transmission unit (MTU) size, type of communication, and CPU entitlement.
Virtual Ethernet support began with IBM AIX Version 5.3, IBM i V5R3, Red Hat Enterprise
Linux 4, and SUSE Linux Enterprise Server, 9, and it is supported on all later versions. (For
more information, see 3.4.8, "Operating system support for PowerVM" on page 129). The
virtual Ethernet is part of the base system configuration.
Virtual Ethernet has the following major features:
The virtual Ethernet adapters can be used for both IPv4 and IPv6 communication and can
transmit packets with a size up to 65,408 bytes. Therefore, the maximum MTU for the
corresponding interface can be up to 65,394 (or 65,390 if VLAN tagging is used).
The POWER Hypervisor presents itself to partitions as a virtual 802.1Q-compliant switch.
The maximum number of VLANs is 4096. Virtual Ethernet adapters can be configured as
either untagged or tagged (following the IEEE 802.1Q VLAN standard).
A partition can support 256 virtual Ethernet adapters. Besides a default port VLAN ID, the
number of additional VLAN ID values that can be assigned per virtual Ethernet adapter is
20, which implies that each virtual Ethernet adapter can be used to access 21 virtual
networks.
Each partition operating system detects the virtual local area network (VLAN) switch as an
Ethernet adapter without the physical link properties and asynchronous data transmit
operations.
Any virtual Ethernet can also have connectivity outside of the server if a Layer 2 bridge to a
physical Ethernet adapter is set in one VIOS partition, also known as Shared Ethernet
Adapter. For more information about shared Ethernet, see 3.4.4, "Virtual I/O Server" on
page 123.
Adapter and access: Virtual Ethernet is based on the IEEE 802.1Q VLAN standard. No
physical I/O adapter is required when creating a VLAN connection between partitions, and
no access to an outside network is required.
client
partitions. The VIOS partition is a special logical partition,
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