Intelligent storage switches, which are being developed by several start-up vendors, could solve the problem of how to manage distributed storage devices.
The key technologies driving storage to date have been storage-area networks, which consolidate storage at the block level; network-attached storage, which provides consolidation and optimization at the file level; and virtualization, which abstracts either block or file resources to make them look like a single, ubiquitous pool.
SANs, NAS and virtualization each help you manage storage more easily. However, when used in isolation they simply make bigger islands of storage, which still need to be managed separately. The logical evolution could be provisioned as well as managed from a single, centralized pool of disks. This could be accomplished with intelligent storage switches.
An intelligent storage switch is built around a protocol-agnostic crossbar switching fabric. The switch fabric ties together other intelligent modular components that support various interfaces and protocols. In doing so, it moves intelligence and management out of the storage arrays and servers, and into the centre of the storage network. The theory is that once the intelligence is in the middle, resources such as server and disk array access can be centrally managed.
An intelligent storage switch provides Ethernet interfaces for access to LANs, MANs and WANs, and file-level access (NAS) or block storage over IP (iSCSI, for example). The switches’ Fibre Channel ports provide block-level access to disk arrays or hosts (or both using Fibre Channel switches). The switch manages protocols and protocol conversions, and houses processing power for functions such as virtualization. Management is housed in the center of the converged IP and storage network.
An intelligent storage switch offers the following advantages:
– Modular design: A modular chassis lets you mix and match protocols and speeds, and upgrade to newer and faster ones as they emerge.
– Multiprotocol support: Database applications tend to be best served by high-performance, block-level SAN access. NAS is best for file serving functions. Disaster recovery applications may require a protocol such as iSCSI. Serverless backup requires an approach such as Network Data Management Protocol. An intelligent storage switch collapses these services into one device.
– In-line virtualization: An intelligent storage switch can centralize disk pooling in a single high-performance device, then present block and/or file entities as appropriate.
– Integrated load balancing: The load balancing function can be as close to the data as possible to decrease the complexity of IP-based load-balancing schemes.
– High-speed data mover at the core: A crossbar switch at the core of the data-moving infrastructure optimizes data moving capacity.
– Carrier-class design for highest availability: Unlike server-based appliances, intelligent storage switches are designed for highest availability.
– Separate disk arrays. Today’s storage architectures lock you in to purchasing disks at whatever prices vendors decide to charge. With an intelligent storage switch, you can purchase higher-end RAID arrays for some applications, and cheap JBOD (just a bunch of disks) for others.
Intelligent storage switches are expected to be available from a number of start-up vendors this fall. Additionally, many incumbent switch vendors have announced the intention to fold some of these capabilities into their platforms.
Handlin is a senior product manager with storage networking company Pirus Networks Inc. He can be reached at bhandlin@pirus.com.
