6.0.1

Table Of Contents
File-Based (VMFS) Solution
When you use an ESXi system in conjunction with a SAN, you must decide whether le-based tools are
more suitable for your particular situation.
When you consider a le-based solution that uses VMware tools and VMFS instead of the array tools, be
aware of the following points:
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Using VMware tools and VMFS is beer for provisioning. One large LUN is allocated and
multiple .vmdk les can be placed on that LUN. With an RDM, a new LUN is required for each virtual
machine.
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Snapshoing is included with your ESXi host at no extra cost.
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Using VMFS is easier for ESXi administrators.
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ESXi administrators who use the le-based solution are more independent from the SAN administrator.
Third-Party Management Applications
You can use third-party management applications in conjunction with your ESXi host.
Most SAN hardware is packaged with storage management software. In many cases, this software is a web
application that can be used with any web browser connected to your network. In other cases, this software
typically runs on the storage system or on a single server, independent of the servers that use the SAN for
storage.
Use this third-party management software for the following tasks:
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Storage array management, including LUN creation, array cache management, LUN mapping, and
LUN security.
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Seing up replication, check points, snapshots, or mirroring.
If you decide to run the SAN management software on a virtual machine, you gain the benets of running a
virtual machine, including failover using vMotion and VMware HA. Because of the additional level of
indirection, however, the management software might not be able to see the SAN. In this case, you can use
an RDM.
N Whether a virtual machine can run management software successfully depends on the particular
storage system.
SAN Storage Backup Considerations
Having a proper backup strategy is one of the most important aspects of SAN management. In the SAN
environment, backups have two goals. The rst goal is to archive online data to oine media. This process
is repeated periodically for all online data on a time schedule. The second goal is to provide access to oine
data for recovery from a problem. For example, database recovery often requires retrieval of archived log
les that are not currently online.
Scheduling a backup depends on a number of factors:
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Identication of critical applications that require more frequent backup cycles within a given period of
time.
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Recovery point and recovery time goals. Consider how precise your recovery point needs to be, and
how long you are willing to wait for it.
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The rate of change (RoC) associated with the data. For example, if you are using
synchronous/asynchronous replication, the RoC aects the amount of bandwidth required between the
primary and secondary storage devices.
vSphere Storage
32 VMware, Inc.