xStack Storage DSN-Series SAN Arrays
VMware ESX 3.0.2 & 3.5
D-Link Systems, Inc. Page
22
December 2, 2009
Performance Tuning
Tuning your environment is very important. ALWAYS update the BIOS, firmware, drivers, and
patches to the latest and greatest version. By doing so, you may circumvent a problem before you
even get to it. Test your design in the lab before you put it into production. You can design the
best system on paper, but due to issues that you might not be aware of, your design may not
deliver optimal performance.
If you are looking to squeeze every ounce of speed out of your SAN environment, you will want
to create multiple RAID arrays and deliver each array to a separate server. This way the IO of one
server and the spindles it uses will not affect the others but if you are planning to do this, you will
need to plan carefully how you plan on using your SAN. If you need to reconfigure your SAN at
a later time, you may need to delete one or more arrays and start again.
If at all possible, you should build a separate iSCSI network for your SAN environment. Yes, you
can connect your SAN to the existing gig-e network and mount its drives from another building
but you may pay a performance penalty by doing so plus you are competing with normal network
traffic. As applications begin using more and more of a gigabyte connection or others begin using
the bandwidth for video streaming, MP3 downloading, or whatever, if you elect to put your SAN
on a normal communications network, be prepared for the day when you will need to move it.
One case in which you may wish to put one leg of your SAN on a corporate network is when you
are conducting SAN to SAN replication. With the D-Link xStack Storage series SAN, you can
limit the amount of bandwidth you allocate for replication.
SUMMARY
VMware Virtual Infrastructure gives customers several methods of providing storage to virtual
machines. Each of these storage methods enables customers to have flexibility in their
infrastructure design, which in turn provides cost savings, increased storage utilization, and
enhanced data recovery. This technical report is not intended to be a definitive implementation or
solutions guide. Expertise may be required to solve user-specific deployments.
Conclusions and Recommendations
In conclusion, the D-Link xStack Storage series SAN is an excellent value for the money and
offers high end features with a reasonable price tag. Combine it with VMWare ESX (or other
virtual) server, and you have the major tools you need to build a state-of-the-art server
environment without breaking your budget.
The xStack Storage Series provides a range of performance and functionality that match the
various levels of iSCSI storage applications and user environments.
For those datacenters and businesses requiring fast and robust storage, especially those who
already have made investments in elaborate hardware and expertise, the xStack Storage Series
iSCSI provides a ready means to deploy large iSCSI SANs either standalone or in conjunction
with existing (Fibre Channel) SANs.
