Of course, you could cluster a couple of NetApp boxes together and
get failover, but they were still two boxes running two (or more)
separate instances of file systems and applications. On the block
side, you couldn't even do that. The two Clariions always acted and
behaved like two separate boxes, unless you used dual path
software, in which case you could get an application to failover
from one storage box to another. That was all good for the 20th
century.
Then, a couple of smart guys in Colorado decided to build
storage systems using IP as transport, initially using a
proprietary protocol (and eventually replacing that with
iSCSI). But, they didn't just do a box. They
added clustering in a novel way so that one could start with two
nodes and (at least, theoretically) add nodes ad infinitum. This
clustering is for more than high availability. It is for scaling
performance, capacity, I/O and yes, high availability. That
single event changed block storage for ever. There are systems
from LeftHand Networks, EqualLogic and one expected soon from
Pivot3.
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The same thing has happened on the file side. A couple of guys in a
garage, granted their garage was bigger than most mansions in
Newport, R.I., decided to use a clustered file system to build a
powerful
NAS box that essentially did for files what
the iSCSI box did for block storage. It gave you a "start small,
pay as you grow" NAS that still looked and behaved like a single
box from a management perspective. Think of this as file
virtualization and HA [high availability] combined, if you will.
This event also changed NAS forever. Now, we have powerful
offerings from Isilon, Exanet, PolyServe and NetApp (GX), and
several others in the market. And frankly, the impact of this
event is still in its infancy. Ninety-five percent plus of the
NAS out there is still the garden variety.
That brings me to the main thrust of my observation here: Why
have we not seen any Fibre Channel-based block storage that follows
the same philosophy as iSCSI or NFS/CIFS? Is it that there is an
inherent technology problem making this happen on the Fibre Channel
side? Why is the concept good for one and not for the other? Or, is
it that the "two guys in a garage" are, in fact, working on
building one, and it is simply a matter of time until we will see
these systems emerge.
I have done some digging into this area and have basically come
to the conclusion that the technology required exists, the concept
makes infinite sense, but once again the big guys are too caught up
with NIH (not invented here) and protection of their monolithic
storage to really do anything about it. To make it work one has to
start afresh, look at the set of new storage network chips, Astute
Networks, iVivit, Aristos Logic, Aarohi (now Emulex), for instance,
available in the market that, in my view, are required for
performance and scalability, and yank out a system superior to
anything in the market right now. I always thought it would be a
Compellent or a 3PAR that would have done this. They both applied
novel technologies, but within the context of traditional
architectures.
OK, that was indeed progress. But an "infinite" storage system
based on Fibre Channel could keep Fibre Channel in the game for a
very long time. It is not uncommon for the purveyors of Fibre
Channel storage to cry on my shoulders about how poor iSCSI
performance really is, and how it is faking its way into the data
center. To that I say, "bull." As I have indicated many times
before, it wasn't the iSCSI protocol that got iSCSI moving, it was
the way the protocol was implemented in a clustered fashion. The
ease of use so commonly associated with iSCSI has nothing to do
with the protocol. It has to do with the novel way in which it was
implemented.
I believe the first major player that develops and ships a Fibre
Channel equivalent of clustered block storage will run away with
the prize. But, it will come at a price. The new storage will
indeed impact the monolithic storage (EMC Symmetrix, IBM Shark, HDS
Lightning) revenues for a while. But, as we all know, in technology
business, we either eat our own children or competition eats them
and us, in one gulp.
So who will be the first one to take this major step? The
gauntlet is thrown!
About the author: Arun Taneja is the founder and consulting
analyst for the Taneja Group. Taneja writes columns and answers
questions about data management and related topics.