Vendors move toward fabric-based intelligence

By Heidi Biggar

Although initial shipments of "intelligent" switches are still several months out, a variety of hardware and software vendors are already in queue to grab a share of this emerging market—a market analysts say is set to take off next year.

"It is absolutely the way to go," says Arun Taneja, consulting analyst and founder of the Taneja Group, in Hopkinton, MA, about the prospect of moving certain storage services (e.g., replication, migration, and virtualization) off hosts and disk systems and into the network on specially designed switches.

Brocade, MaXXan Systems, and most recently Cisco have outlined strategies for this developing market space. And at this juncture, Cisco may have an early lead ahead of market-share leader Brocade. Brocade is reportedly having difficulty reconciling its inherited intelligent switch platform (acquired from Rhapsody Networks earlier this year) with its existing SilkWorm line. Cisco acquired its intelligent switching platform from Andiamo Systems last year.

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"We've been working with Cisco a lot longer, so it's my guess that we'll come out first with Cisco," says Jose Iglesias, vice president of integrated products, at Veritas Software.

Iglesias says Veritas could make its SAN Volume Manager (VM) software for MDS switches generally available in the next quarter. The two companies demonstrated the technology (Veritas SAN VM running on Cisco MDS 9509 multi-layer directors) at Veritas Vision last month. Veritas has not yet announced an availability date for SAN VM running on the Brocade SilkWorm Fabric Application Platform.

In addition to Veritas, Cisco says it is actively working with EMC and HP, among others, to port management applications to the Cisco platform. Though quiet about its relationship with Cisco, HP has publicly stated that it is currently developing its Continuous Access Storage Appliance (CASA) to work with the MDS 9000 Fibre Channel switches.

CASA is an in-band virtualization appliance that is designed to provide heterogeneous disk/host support. HP acquired the technology from StorageApps in 2001 (see "HP to merge virtualization platforms," InfoStor, March 2003, p. 8).

HP is also working with Brocade on similar product development. Other Brocade application partners include Alacritus,

CommVault, FalconStor, Hewlett-Packard, Incipient, InterSAN, StoreAge, and Topio (see "Fabric-based intelligence gets vendor nod," InfoStor, April 2003, p. 8).

The question being raised today isn't necessarily whether network-based management makes sense (though some analysts say its purpose is not clear-cut), but which applications will be ported to these switches and whether users will buy into the concept.

Vendors, not end users, are driving this technology shift, says Taneja.

Nonetheless, when presented with the idea of running applications directly from the network, users seem to be responding favorably. In fact, in a recent InfoStor QuickVote, 38% of survey respondents said they would actually prefer to run their applications from switches. Forty-one percent said they would prefer to run them in disk arrays, while 21% checked off the host as their preferred site (see figure above).

Ultimately, decisions about where to put the intelligence in storage environments comes down to three issues: cost, performance, and availability, says Chris Gahagan, senior vice president of storage infrastructure software at EMC. "And I don't believe that means putting all the intelligence in the network."

"It's not a black-and-white issue," says Taneja. Users have a love-hate relationship with the way things currently work, he says. "They love some things about disk-based intelligence [e.g., some of the fine-tuned capabilities], but they hate others [e.g., the fact that they have to pay a huge price for the capability]."

"One particular application that users are trying out in the network is data replication," says John Webster, president and founder of the Data Mobility Group. Other potential applications include data migration, replication, volume management/virtualization, and backup and recovery.

While array-based replication may be more familiar to users (and may even provide better performance) than network-based alternatives, it can be costly and can potentially put you in a vendor lock-in situation, explains Webster. "Network-based replication allows users to break away from proprietary software and the high costs of today's replication products."

Embedding replication software in an intelligent switch—one that supports heterogeneous hardware, software, and operating systems—enables users to replicate data between any two boxes, regardless of the vendor.

While Taneja agrees that replication is a key application to move into the network, he doesn't expect vendors like EMC to port high-end software like SRDF or TimeFinder to the new breed of switches in the near future.

"EMC is a smart company and they know which way the wind is blowing, ... [but] SRDF was designed specifically for replication between their boxes. They would have to start from scratch to do any-to-any replication."

Gahagan says that while EMC is working to port a variety of applications to both Brocade and Cisco intelligent switching platforms, the company has no immediate plans to move SRDF or TimeFinder out of the disk array and onto the network. Instead, EMC will focus on porting volume management and data mobility applications (e.g., data migration) to these devices.

EMC last month released a new version of its PowerPath software, which features an integrated volume manager—a first for the storage goliath. (The software will compete with products like Veritas Volume Manager.) The company says it plans to release an enhanced version of the software in the third quarter, which will be capable of transparently moving online application data from one array to another (EMC or non-EMC) array without affecting application performance and availability.

The first release of this software will have limited disk support, but "full" heterogeneous support, including all leading arrays, is slated for year-end. The software will be released for host environments first; a network version will be released later this year.

Explains EMC's Gahagan: We're not trying to re-invent what we've already done, but to automate key management tasks (e.g., auto-configuring new storage and servers). "The disk array's job is to make sure data is always preserved. The network is responsible for the delivery of data from the array to the host [and that] requires an understanding of the LUNs and volumes that it is working with."

PowerPath is the first step toward that level of intelligence, contends Gahagan. The next step will be to move services into the network that will help administrators auto-configure their storage/server environments. These products will let users set QoS requirements at the LUN level, match high-level LUNs to high-value applications, and move storage online and offline as needed.

"It's naive to think that you can move this level of sophistication into the network overnight, but we believe that the days of [administrators] having to be involved when new storage and servers are added will go away."

The advantages of moving these types of applications and others into the network include improved/simplified management, improved scalability, better host performance, migration, investment protection, and possibly lower cost.

Traditional host- and disk-based management techniques, in contrast, tend to be difficult to manage (requiring multiple management tools and many pieces of software) and scale, and can lock users into a specific vendor brand or model. Additionally, network management tools will enable users to migrate data off expensive disk and onto less-expensive disk for lower overall storage costs. But don't look for a true price break: Vendors will likely make up any difference in cost by charging on a per-gigabyte/terabyte basis.

This article was originally published on June 01, 2003