Andrew Knippen, network administrator at Citizens National Bank in Bluffton, Ohio, wasn't rushing to get rid of his servers' internal or direct-attached storage (DAS). They had served
"In our virtualized environment, we wanted to have all seven branches' storage tied back to main office so that everyone could have access to the data and we could put in place a disaster recovery [DR] plan," Knippen said. It was critical to do this without spending a lot of money or needing dedicated staff, he adds.
Knippen deployed two Dell Equallogic PS5000x entry-level SANs -- one at the main office and one off-site -- to gain the redundancy he needed for business continuity. He said the all-in-one PS5000x boxes, which together cost $60,000, mirror each other and are used to support the bank's email, database, domain controller, Web and application server environments. In addition, the main office box features dual controllers with three NICs each for built-in failover. The off-site unit has a single controller.
The key factor in keeping the costs down was choosing an iSCSI-based entry-level storage area network rather than a Fibre Channel (FC) offering. With an iSCSI SAN, he could take advantage of the bank's ubiquitous Ethernet and existing staff skills. "iSCSI is so much easier for our environment. It didn't tie us down to having expensive Fibre Channel installed. Also, no one here is certified in Fibre Channel, so we would have had to send staff for training," he said.
iSCSI SANs popular in SMB storage market
The combination of lower cost and less complexity is making iSCSI a contender in the market of SANs targeted at SMBs, according to Jeff Byrne, senior analyst at the Taneja Group in Hopkinton, Mass. In fact, some of the biggest names in storage, including EMC Corp., Hewlett Packard (HP) Co., IBM Corp. and NetApp, cater to this market, even if they also have Fibre Channel offerings. For instance, EMC offers its Celerra NS-GS IP storage gateway platform; HP has its StorageWorks 4400 and LeftHand P4000; IBM boasts its System Storage DS3300 series; and NetApp FAS250 and 270 -- all of which support iSCSI.
While larger organizations are drawn to Fibre Channel and overlook its cost and complexity in favor of its speed, low latency and expert ability to handle I/O-intensive data transfers, SMBs do not have the same requirements. "iSCSI is more than adequate for the majority of applications being run in the small business market … so I definitely think that iSCSI can outpace Fibre Channel in the SMB space," Byrne said. A recent survey his firm conducted of nearly 400 IT professionals shows that iSCSI is already in use for at least some storage among half of SMB companies. And he adds the continued adoption of virtualized server environments will push this number higher.
Another attractive feature of iSCSI for SMBs is its total cost of ownership. "iSCSI-based SANs are lower cost, can leverage existing network infrastructure such as gigabit network cards and gigabit switches, and are easy to implement as most IT personnel are familiar with the technology," said Joyce Tang, managing consultant at AgilisIT in San Diego. "As more SMBs migrate to SANs due to increased storage requirements, they will need cost-effective solutions and it will be the solution that has the best bang for the buck that will win out."
Byrne agrees that the economics of SANs vs. direct-attached storage are getting better, in major part thanks to iSCSI. "Five years ago, direct-attached storage would have been half the cost of a SAN, if not less. Today, there is more parity and SAN starter kits, which are available for less than $10,000, are within the reach of SMB budgets," Byrne said.
Hybrid SANs working for some SMBs
While some SMBs are looking for a pure iSCSI approach, John Meade, systems analyst II at Utah's Provo City Library at Academy Square, said he's enjoying the best of both worlds with a hybrid approach from Compellent.
Like Knippen, Meade migrated from direct-attached storage when he virtualized his 15 physical servers that support the library's application, domain, Web, catalog, RFID and email systems.
The QuickStart SE bundle, an entry-level SAN starter kit that interoperates with VMware's ESX Server and starts at about $25,500, uses iSCSI between the controller and VMware server and Fibre Channel between the controller and the storage drive. Meade said this gives his team the throughput they need to support highly transactional applications without the need for Fibre Channel expertise.
Though many entry-level SANs, including the PS5000x and the QuickStart SE, offer bells and whistles such as thin provisioning, snapshots, data deduplication and tiered storage, most SMBs are focused on simplicity. "At the SMB level, they're not going to play with all the extras and they usually only use one type of storage, not multiple tiers," Tang said.
While entry-level offerings can make SANs attractive, they aren't for everyone. "You have to have a real need for shared storage to buy a SAN. A small company with a single headquarters location and remote workers would be the ideal candidate." she said.
About this author: Sandra Gittlen is a freelance technology editor in the greater Boston area. She can be reached at firstname.lastname@example.org.