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Table Of Contents
Using ESXi with Fibre Channel
SAN 4
When you set up ESXi hosts to use FC SAN storage arrays, special considerations are necessary. This
section provides introductory information about how to use ESXi with an FC SAN array.
This chapter includes the following topics:
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Fibre Channel SAN Concepts
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Using Zoning with Fibre Channel SANs
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How Virtual Machines Access Data on a Fibre Channel SAN
Fibre Channel SAN Concepts
If you are an ESXi administrator planning to set up hosts to work with SANs, you must have a working
knowledge of SAN concepts. You can find information about SANs in print and on the Internet. Because
this industry changes constantly, check these resources frequently.
If you are new to SAN technology, familiarize yourself with the basic terminology.
A storage area network (SAN) is a specialized high-speed network that connects host servers to high-
performance storage subsystems. The SAN components include host bus adapters (HBAs) in the host
servers, switches that help route storage traffic, cables, storage processors (SPs), and storage disk
arrays.
A SAN topology with at least one switch present on the network forms a SAN fabric.
To transfer traffic from host servers to shared storage, the SAN uses the Fibre Channel (FC) protocol that
packages SCSI commands into Fibre Channel frames.
To restrict server access to storage arrays not allocated to that server, the SAN uses zoning. Typically,
zones are created for each group of servers that access a shared group of storage devices and LUNs.
Zones define which HBAs can connect to which SPs. Devices outside a zone are not visible to the
devices inside the zone.
Zoning is similar to LUN masking, which is commonly used for permission management. LUN masking is
a process that makes a LUN available to some hosts and unavailable to other hosts.
When transferring data between the host server and storage, the SAN uses a technique known as
multipathing. Multipathing allows you to have more than one physical path from the ESXi host to a LUN
on a storage system.
VMware, Inc.
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