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The poor man's SAN

Branch offices, remote sites and smaller organisations are looking at the cost and simplicity of IP storage.

As companies update their storage wardrobe and cloak themselves in modern garb, IP solutions are finally being accepted as a viable networked storage option. They have made great strides since debuting in 2003.

IP storage is a general term covering several approaches to using Internet Prototol (IP) in a storage area network (SAN) usually over Gigabit Ethernet. It is an alternative to the Fibre Channel framework of traditional SANs.

Industry experts claim IP storage offers a number of benefits over Fibre Channel alternatives. Fibre Channel issues include expense, complexity and interoperability. With IP SANs, the hardware components are less expensive, the technologies are widely known. There are few interoperability issues and training costs are lower.

Storage Networking Industry Association (SNIA) IP storage forum chair, David Dale, said it's been a slow, but steady uptake.

He said the technology was finally broadening the options available to IT executives to address the cost, availability, performance and manageability issues caused by continual data growth.

Many companies are analysing the savings they can achieve by replacing direct-attached storage with an IP storage area network (SAN) solution. Rather than opt for the traditional Fibre Channel SAN in all business scenarios, which can be costly and tricky to implement, many companies are choosing to throw IP storage into the equation.

Industry shift

Calling IP storage the poor man's SAN, AustSTOR Data Storage business development manager, Bruce Macdonald, said the value-added storage distributor was seeing an industry wide shift towards IP technology.

"We're seeing many of our vendors provide iSCSI connectivity as a standard feature," he said. "IP storage continues to make inroads as customers look to move more data to remote disaster recovery data centres seamlessly."

He said IP storage and WAN accelerator technology would have a big play in the disaster recovery market. Its native transport medium means there are few upfront infrastructure costs.

IP SANs typically fall into one of two categories: those that use an Ethernet link to interconnect Fibre Channel SAN environments via gateways; and those where a SAN is built using Gigabit Ethernet infrastructure instead of Fibre Channel.

SNIA's Dale said IP SANs leveraged a company's existing investment in the Ethernet infrastructure. "It offers more affordable SAN storage, support for all applications, lowers the total cost of ownership and infrastructure complexity, and is manageable by existing server administrative staff," he said.

Dale is not alone in his bullish forecasts. Many analysts now view iSCSI SAN as a mainstream solution for Windows server environments in medium and large organisations, with estimates that more than 6000 customers worldwide have deployed iSCSI-based SAN solutions.

IDC views iSCSI as the fastest-growing area of the storage market - with an expected 211 per cent compound annual growth for 2005-2009 to reach a value of $US2.65 billion.

IDC senior storage analyst, Graham Penn, said IP storage was providing affordable new SAN storage solutions in parts of the IT infrastructure that are still dominated by direct-attached storage.

Penn said the technology was ideal for regional and departmental data centres and across various remote offices. The applications running in these smaller environments might not be mission-critical, so they didn't require the mighty performance of a Fibre Channel SAN, but they were still business critical and would be well suited to the flexibility of iSCSI technology.

"We're not seeing any wholesale replacement of Fibre Channel in the data centre at this point," Penn said. "Customers are sticking with it as it would be too costly to change.

"But the prospect of simpler, lower cost technology is driving the IP push. People better understand IP, while there's a limited understanding of Fibre Channel."

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Market sweet spot

SNIA's Dale said IP storage was being deployed primarily in environments dominated by mid-range and low-end servers. The servers are likely to be Intel-architecture servers running Windows, Novell NetWare or Linux operating systems. "Building affordable SANs is a good match for low-cost servers," he said.

Like Dale, Network Appliance marketing and alliances director, Mark Heers, said IP SANs had a very specific purpose, and were ideal at a remote or branch office, or in conjunction with the main Fibre Channel SAN as they extended and complemented existing environments.

"The majority of the market is singing the Fibre Channel tune," Heers said. "The IP SAN install base is small, but it's growing. We're out of the early adopter phase and into the maturity phase. It's now an accepted technology, and a decent number of vendors have an iSCSI offering."

The majority of IP users are entering the network storage arena for the first time. These companies want the ease of use and cost benefits associated with managing an IP SAN versus Fibre Channel.

"People going for iSCSI are new to the network storage arena and don't want the expense of going for Fibre Channel," Heers said.

Secondary SAN

Climbing up the food chain, larger organisations may opt for an IP SAN as a secondary networking method where Fibre Channel may be too costly and unnecessary to have at the departmental or branch office site.

EMC director of marketing, Clive Gold, said larger organisations that want to capture stranded servers - perhaps older ones - are likely adoption spots for iSCSI technology.

"There are two market segments: smaller customers that want to run applications that are low value and determine the cost of putting in Fibre Channel wouldn't be worth it; and larger customers that want to hook up their data centres at regional and departmental offices."

In these environments, the data centre looks different than the core data centre with the servers being smaller and more numerous. According to SNIA, the need for network storage solutions is likely to be most acute here, although the penetration of networked storage is only likely to be about 30 per cent.

It said IP storage made significant advances on several fronts last year. On the standards front, the most recent version of the Storage Management Initiative Specification, SMI-S version 1.1, now includes support for iSCSI.

This year, and last year, was a breakout year for iSCSI as the industry continues to see significant product releases from server and storage platform vendors, and more and more vendors entering the market, Dale said.

Industry experts agree Microsoft's endorsement of the technology signalled a positive step forward with the company announcing iSCSI support in Exchange, SQL Server and in Windows OS.

"The Microsoft support was developed in the last 12 months and is the most notable market mover," NetApp's Heers said. "The other huge move was VMware's support of iSCSI."

In addition to vendor endorsement, users and resellers are attracted to the relative ease of use and simple installation associated with an IP SAN compared to the complexity associated with Fibre Channel and the required expertise.

"IP is a straightforward technology to use. Resellers already have the appropriate knowledge base to set it up and understand standard Ethernet networking," Heers said. Smaller organisations, with limited IT staff, would be better able to decipher the IP technology rather than the skills needed to hook up Fibre Channel.

"Fibre Channel is complex and not something that the average, solo IT person would understand," Heers said. "It's a technology that's a little more specialised. It's something that larger organisations would be more capable of implementing."

SNIA's Dale said iSCSI, meanwhile, represented a big selling opportunity for resellers in terms of professional services. "Resellers can do SQL Server or Exchange migration. It's a big opportunity for differentiation because they can do OS platform migration services attached to this." While the most popular applications in an iSCSI environment are Microsoft Exchange, SQL Server and business applications running on top of smaller Oracle or IBM DB2 databases, messaging, Web, ecommerce and some technical applications are also a good fit with iSCSI environments, he said.

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Speed boost

The promise of 10GB Ethernet is on the lips of many vendors offering iSCSI. "It is in laboratories now," Heers said. "We'll start to see it next year. It's not going to overthrow Fibre Channel, but it will ramp up speed."

In addition to souped up speed, the best scenario for customers was to have the choice in terms of connecting the two technologies, Heers said indicating NetApp products can support both Fibre Channel and iSCSI.

"Users can connect both, and run different chunks of applications at the same time," he said. "One piece could be Fibre Channel, while the other iSCSI, which would be all wired to the same infrastructure. It will run SAN/NAS and iSCSI protocols."

Heers said a third of NetApp customers run at least two of the three protocols. "The industry is moving towards offering this choice. It makes it easier for customers."

EMC's Gold said the company is also offering customers a choice between the two protocols, and moving away from the lock-in approach. "Many vendors may say they support both protocols, but under the covers, there are restrictions," he said.

Like Heers, Gold looks forward to the rollout of 10GB Ethernet. "Once this comes out, you'll have a quantum leap of IP technology in terms of speed, so the speed argument will disappear.

"At the end of the day, we shouldn't get into religious wars about this stuff. There will be demand for both Fibre Channel and iSCSI. Fibre Channel will handle the large data loads, mission-critical, high throughput zones, while IP will bring in the stranded servers and work well in remote sites or branch offices."