Datasheet

infraStructure SerViceS

iSCSI support improvements In vSphere 4, VMware has rewritten the entire iSCSI software

initiator stack for both software iSCSI (that is, in which the iSCSI initiator runs at the ESX layer)

and hardware iSCSI (that is, in which ESX leverages a hardware-optimized iSCSI HBA). As

a result, both software and hardware iSCSI in vSphere 4 provide better throughput and CPU

efﬁciency when compared to the earlier 3.5 version.

VMdi r e c t Pa t h i/o F o r St o r a g e

VMDirectPath I/O is a new capability in vSphere that enables virtual machines to directly

access the underlying physical I/O devices. When using VMDirectPath I/O for storage, there

is a one-to-one mapping between an HBA and a VM, and you are not allowed to share an HBA

by more than one VM. VMDirectPath is designed to handle the I/O needs of special-purpose

I/O appliances and I/O-intensive virtual machines. By accessing the I/O devices directly and

bypassing the hypervisor, the guest OS enhances CPU efﬁciency in handling the high I/O work-

loads. However, this I/O throughput scalability comes at the cost of other virtualization fea-

tures. Features such as VMotion, hardware independence, and sharing of physical I/O devices

are not available for virtual machines using VMDirectPath I/O.

In vSphere 4.0, VMDirectPath I/O is experimentally supported for the following storage I/O

devices:

QLogic QLA25xx 8 Gb Fibre Channel adapters

•u

Emulex LPe12000 8 Gb Fibre Channel adapters•u

LSI 3442e-R and 3801e (1068 chip based) 3 Gb SAS adapters•u

VMware vNetwork

VMware vNetwork provides features to help you deploy and manage enterprise-class virtual

networking that can communicate with external physical networks. It comprises the following

key features:

Virtual network adapters

•u enable network virtualization by allowing virtual machines to net-

work like physical machines do. VMware provides three types of virtual network adapters

that virtual machines can use. vSphere introduces the third generation of the paravirtual-

ized in-guest network drivers (VMXNET3) for enhanced network I/O performance.

The VMware vNetwork

•u Standard Switch enables you to create a virtual network between

virtual machines within a single VMware ESX/ESXi host as well as those on the outside

physical network. These virtual switches support the same networking protocols as physi-

cal switches and implement enterprise-class features such as VLANs and hardware NIC

teaming for availability and performance.

The VMware vNetwork

•u Distributed Switch moves beyond per-host network conﬁguration

and simpliﬁes networking management across multiple hosts in VMware vSphere envi-

ronments from one central interface. It also enables third-party distributed virtual switches

such as the Cisco Nexus 1000V Series virtual switch to be used in VMware vSphere environ-

ments so that network administrators can use familiar interfaces when managing virtual

networking.

We will discuss each of these vNetwork services in detail in the next sections.

563601c01.indd 15 6/29/10 4:41:02 PM