|
Introduction to IP SAN
There is no question that the Internet is
becoming the predominant media for carrying massive amounts of digital
information in an expanding digitized world and in a highly redundant,
distributed, and resilient way—much more so than its original designers could
have imagined. Increasingly, the Internet functions as the backbone not only
for email (email being the single most used and most mission critical
application of all) but also for all sorts of raw data, financial information,
knowledge content, and business transactions. The Internet also carries voice
(in the form of Internet-based, long distance telephone), video and, if things
go the way I think they will, a virtually boundless digital storage medium for
the masses.
As we continue to digitize anything and
everything that has that capacity, the requirement for storage, specifically
network storage, increases in an ever-growing rate. Our existing digital
storage architecture as it stands today is just not going to cut it in the long
term. The issues relate to the fact that the existing architecture is
non-scalable and that additional storage growing based on the old architecture
is expensive and complicated to deploy and to maintain in order to keep up with
the current growth. For additional information on this issue, please refer to
our white paper on
Computer Storage Architecture.
During the last four years or so, a new
development has progressively caught on. Although it is a bit early to predict
that it will be the definitive answer for all networked storage needs, it has at
least proven during the last few years to be the first step in finding an answer
for the coming generation of networked storage needs. What is it? Internet
Protocol Storage Area Network (IP SAN). Not a new concept, IP SAN is based on
the traditional Fiber Channel (FC) SAN. (Also see
Computer Storage Architecture.) The one new thing about it is that it uses
TCP/IP as its media, rather than FC. As we all know by now, the Transmission
Control Protocol (TCP) and the Internet Protocol (IP) is part of the backbone of
the Internet’s suite of communication protocols. The beauty behind IP SAN is
that when it is utilized, networked storage can be available any place TCP/IP
goes. And that is everywhere.
IP SAN has the advantage of not requiring
special hardware to deploy it because for the most part its implementation is
based entirely on existing technology with a layer of software implementation on
both the client and server side. With the appropriate IP SAN software, a
regular server can be turned into an IP SAN server without needing to purchase
any additional hardware.
There are IP SAN manufacturers making products
specifically for serving the network storage market. Most of today’s IP SAN
manufacturers would like you to think that their hardware implementation is the
best option, but I think at the end of the day, software management tools are
where the main differences will lie. There may be differences currently in
hardware quality, scalability, and performance, but in time all manufacturers
will offer more or less the same product. Since the components these
manufacturers use are pretty much coming from the same sources, there is only so
much they can do to make their product different. And since all of them are
using the same iSCSI standard implementation, the communication layer in the
software is also the same. As a result, the manufacturers that can provide more
advanced software management tools will be the ones providing greater value.
Traditionally, Small Computer System Interface
SCSI is one of the standard interfaces and command sets for transferring data
between devices in both internal and external computing devices. The command
set is how a computer “speaks” to the disk storage.
Internet SCSI (iSCSI) uses the same SCSI command
set to communicate between the computing devices and storage, via a TCP/IP
network. IP SAN uses TCP as a transport mechanism for storage over Ethernet,
and iSCSI encapsulates SCSI commands into TCP packets, thus enabling the
transport of I/O block data over IP networks.
Below are the iSCSI and IP SAN architecture
block diagrams
iSCSI has proven itself able to handle the
demands of high-performance computing applications such as simultaneous
visualization and high-volume transactional databases, just like most of the FC
SAN can do. In my opinion, the debate will be resolved if iSCSI can perform
well for 90% of what FC SAN is doing currently. In fact, with the introduction
of 10 gigabit Ethernet, I can foresee it performing better than today’s FC SAN.
I am sure though that the FC SAN market will
still be around and further developed. And there are efforts being made
currently to allow FC SAN using TCP/IP as the transport layer to overcome its
distance limitations so that the technology can be used in a geographically
distributed environment, i.e. the Internet.
I
am also certain that IP SAN using iSCSI technology is just one of the steps in
the evolution to the more robust and transparent networked storage technology
that our future demands. I envision a networked storage technology that will
work well with all traditional storage needs and a wave of new-generation mobile
applications compatible with multiple wireless standards.
By
Benson Yeung, Senior Partner
Benson Yeung Biography
Back to Top
Information Request Form
Select the items that apply, and then let us know how to contact you.
|
