Report: Switch Is Best for Virtualization

Despite claims to the contrary, the intelligent SAN switch is the natural host for a range of services, including virtualization, data replication, and mirroring, according to the latest report from the Byte and Switch Insider subscription research service.

The SAN switch is the only place from which services can run backwards and forwards in a storage network, the report states. In contrast, putting virtualization features on servers addresses the front-end of a SAN, where applications are delivered to end users, while putting them in storage arrays restricts them to the back end. Switch services also scale better and can overcome limitations of incompatible server operating systems and multivendor storage arrays, the report says.

The entry into the storage market of the networking giant Cisco Systems Inc. (Nasdaq: CSCO) has added another, less technical, spur to adopt switch-based virtualization. Cisco has introduced serious price competition for SAN switch vendors, which are now eager to augment their wares with new capabilities.

Brocade Communications Systems Inc. (Nasdaq: BRCD) and McData Corp. (Nasdaq: MCDTA) have signed up partners great and small to port applications to their switches and thereby enhance their appeal. MaXXan Systems Inc. is adding ISV software to its NAS appliances as well as SAN switches.

StoreAge Networking Technologies Ltd. and FalconStor Software Inc. (Nasdaq: FALC) have been among those most eager to port their applications to switches, and EMC Corp. (NYSE: EMC) has hooked up with a slew of partners, besides saying it's developing virtualization software for its own gear.Cisco's got its own irons in the fire. Besides working with EMC, it counts Hewlett-Packard Co. (NYSE: HPQ), IBM Corp. (NYSE: IBM), and Veritas Software Corp. (Nasdaq: VRTS), plus another application vendor it will not name, as contributors to its switch applications, which usually turn up as blades in Cisco's MDS9000 box.

Table 1: Intelligent Switch Vendors' Virtualization Partnerships

All these developments have made headlines over the last few months (see Switch Showoffs Prep for Show, EMC & McData Get Smart, Veritas Finally Delivers on Cisco, and Cisco & IBM Serve Virtual Combo). But not everyone sees the SAN switch as the ideal home for virtualization (see Wisdom of Smart Switch Questioned). Among the 19 companies the report profiles in detail, including those listed elsewhere in this article, as well as DataCore Software Corp., Incipient Inc., MonoSphere Inc., Red Hat Inc. (Nasdaq: RHAT), StoneFly Networks Inc., Sun Microsystems Inc. (Nasdaq: SUNW), and Troika Networks, makers of storage subsystems and appliances claim their wares are better than switches for virtualization.

Candera Inc. and Maranti Networks Inc., for example, offer controllers that contain purpose-built hardware they say introduces less latency into the network than switches do (see More Money for Maranti and Candera Back for Seconds).

The issues articulated and clarified in this report are being mulled by a range of SAN adopters. In a recent Byte and Switch poll, for instance, 59 percent of readers listed the SAN switch as the best place for intelligent functions such as replication to take place; 15 percent said the server, and 26 percent storage arrays.At the same time, 45 percent of respondents said they were "totally unsure" whether to change the location of intelligent functions, and 41 percent are concerned that too much switch intelligence locks them into a single vendor's solution.

Mary Jander, Site Editor, Byte and Switch

The new report is available as part of an annual subscription to the monthly Byte and Switch Insider