iSCSI is the future of storage

iSCSI is here to stay and will eventually supplant a significant portion of the installed base of Fibre Channel SANs out there. Further, as organizations make their initial forays into block-level shared storage, iSCSI will beat Fibre Channel more often than not.

This week, HP announced their $360 million acquisition of LeftHand networks. Last year, Dell surprised the tech industry with a $1.4 billion purchase of the formerly independent EqualLogic.  With these iSCSI snap-ups by true tech titans, iSCSI has officially arrived, is here to stay, and, I believe, will become the technology of choice for most organizations in the future.

This is not to say that iSCSI has been sitting in the background up to this point.  On the contrary, the technology has taken the industry by storm.  Both of these companies based their entire business hopes on the possibility that organizations would see the intrinsic value to be found in iSCSI's simplistic installation and management.  To say that both companies have been successful would be an understatement.

I'm a big fan of both EqualLogic and LeftHand Networks offerings, having purchased an EqualLogic unit in a former life.  At that time, I narrowed my selection down to two options - LeftHand and EqualLogic.  Both solutions had their pros and cons, but both were more than viable.

It's not all about EqualLogic and LeftHand, though.  The big guns in storage have finally jumped feet first into the iSCSI fray with extremely compelling products of their own.  Previously, these players, including EMC and NetApp, simply bolted iSCSI onto existing products.  Lately, even the biggest Fibre Channel vendors are releasing native iSCSI arrays aimed at the mid-tier of the market.  EMC's AX4, for example, is available in both native iSCSI and native Fibre Channel versions and is priced in such a way that any organization considering EqualLogic or LeftHand should make sure to give the EMC AX4 a look.  To be fair, the iSCSI-only AX4:

  • Does not support SAN copy for SAN to SAN replication
  • Is not as easy to install or manage as one of the aforementioned devices, but isn't bad either
  • The bandwidth to the array does not increase as additional space is added
  • It does not include thin provisioning, although this was rumored to be rectified in a future software release
  • The AX4 supports up to 64 attached hosts

But, the price per TB is simply incredible and a solution based on a different vendor would not have been attainable.  This year, I purchased just shy of 14 TB of raw space on a pair of AX4 arrays-4.8 TB SAS and 9 TB SATA-for under $40K. For the foreseeable future, I don't need SAN copy and space can be managed in ways other than through thin provisioning.  Over time, we'll run about two dozen virtual machines on the AX4 along with our administrative databases and Exchange 2007 databases.  By the time I need additional features, the AX4 will be due for replacement anyway.

iSCSI started out at the low end of the market, helping smaller organizations begin to move toward shared storage and away from direct attached solutions.  As time goes on, iSCSI is moving up the food chain and, in many cases, is supplanting small and mid-sized Fibre Channel arrays, particularly in organizations that have never had a SAN before.  As iSCSI continues to take advantage of high-speed SAS disks and begins to use 10Gb Ethernet for a transport mechanism, I see iSCSI continuing to move higher into the market.  Of course, faster, more reliable disks and faster networking capabilities will begin to close the savings gap between iSCSI and Fibre Channel, but iSCSI's reliance on Ethernet for an underlying transport mechanism brings major simplicity to the storage equation and I doubt that iSCSI's costs will ever surpass Fibre Channel anyway, mainly due to the expensive networking hardware needed for significant Fibre Channel implementations.

Even though iSCSI will continue to make inroads further into many organizations, I don't think that iSCSI will ever completely push Fibre Channel out of the way.  Many organizations rely on the raw performance afforded by Fibre Channel and the folks behind Fibre Channel's specifications aren't sitting still.  Every year brings advances to Fibre Channel, including faster disks and improved connection speeds.

In short, I see the iSCSI market continuing to grow very rapidly and, over time, supplanting what would have been Fibre Channel installations.  Further, as organizations continue to expand their storage infrastructures, iSCSI will be a very strong contender, particularly as the solution is updated to take advantage of improvements to the networking speed and disk performance.


Since 1994, Scott Lowe has been providing technology solutions to a variety of organizations. After spending 10 years in multiple CIO roles, Scott is now an independent consultant, blogger, author, owner of The 1610 Group, and a Senior IT Executive w...

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