Installation guide

C H A P T E R 9 Storage and File Systems

323

Using Multipathing in ESX Server

ESX Server 2.1 includes multipathing support to maintain a constant connection

between the server machine and the storage device in case of the failure of a host bus

adapter (HBA), switch, storage controller (or storage processor; abbreviated as SP in

the following diagram), or a Fibre Channel cable. Unlike previous versions of ESX

Server, this version of multipathing support does not require specific failover drivers.

In the preceding diagram, there are multiple, redundant paths from each server to the

storage device. For example, if HBA1, or the link between HBA1 and the Fibre Channel

(FC) switch breaks, HBA2 takes over and provides the connection between the server

and the switch. This process is called HBA failover.

Similarly, if SP1, or the link between SP1 and the switch breaks, SP2 takes over and

provides the connection between the switch and the storage device. This process is

called SP failover. VMware ESX Server 2.1 provides both HBA and SP failover with its

multipathing feature. (SP failover may not be supported by all disk arrays.)

For information on supported SAN hardware, download the VMware ESX Server SAN

Compatibility List from the VMware Web site at www.vmware.com/support/esx2.

SP1 SP2

Storage

HBA 1 HBA 2

Server 1

HBA 3 HBA 4

Server 2

FC Switch