The concept of the "storage switch" started to make sense in the mid-90s when it became clear that data storage complexity was more than businesses could handle. They needed a technology to transport data between servers and storage devices.
Today, the impact of the switch has been nothing less than revolutionary, according to Brad O'Neill, senior analyst and consultant with the Taneja Group, Hopkinton, Mass. "The use of switches have given us storage networking, the rise of the
with its higher utilization rates and the ability to manage terabytes of data," he said.
are devices that channel incoming data from multiple input ports to the specific output port that will take the data toward its intended destination.
In data storage, a switch is essentially a networking device that sits in the data path between a large number of servers and a large number of storage resources. It then plays "traffic cop" between the hosts and storage, enabling information to go back and forth. The area where the storage switch resides is known as a "storage fabric."
Key vendors and products:
Switches can be divided into three groups: entry (under 16 ports), workgroup (16-64 ports) and director (64 ports and up).
In the director switch space, the big three vendors are Brocade Communications Systems Inc. with its SilkWorm line of switches, McData Corp. with the Intrepid switches and Cisco Systems Inc. and its MDS line.
"Computer Network Technology Corp. is also making inroads here with its UltraNet Multi-service Director , but has little market share," said Nancy Hurley, senior analyst, Enterprise Strategy Group (ESG) of Milford, Mass. Up-and-coming director switch startups include Maranti Networks Inc. and Maxxan Systems Inc.
For workgroup switches, Brocade is the market leader with McData and Cisco gaining traction. Again, Brocade is the leader in the entry switch space, with McData and QLogic Corp. following up.
"All of these players have storage switches with a Fibre Channel bias because that is the power base for large enterprises," O'Neill said. However, Brocade, Cisco and McData have been acquiring or building technologies to support an IP
-based storage networking because all realize that IP-based storage is emerging as a powerful technology, O'Neill said.
Innovations and trends:
The most discussed and over-hyped trend in the switching industry is the notion of the "intelligent switch," according to O'Neill. Essentially, an intelligent switch fuels all storage management functionality, from provisioning and discovery to volume management, virtualization
, capacity planning and change management. It makes the storage switch the heart of your entire storage strategy.
"This speaks to the ultimate dream of fabric-centric storage networking, and all of the major switching players have their version of an intelligent switch narrative that they are pushing," O'Neill said.
But, O'Neill has found that end users have varying levels of interest in these propositions, depending on their history and comfort level with SANs. "Most companies today aren't making that wholesale leap into intelligence in the fabric." O'Neill added that most companies are focused on the deployment of more advanced storage functionality on the switch.
Randy Kerns, senior partner at the Evaluator Group in Greenwood Village, Colo., agreed that adding functionality to the switch is the biggest trend going forward. These functionalities include security mechanisms, distance extension with FCIP
(only McData does iFCP), iSCSI
connectivity and SAN routing services. "Routing is a great way to connect different SANs and provide isolation," said Kerns.
ESG's Hurley said that while many are looking to intelligence in the fabric as the next big wave, it won't really hit for another 18 months. Like Kerns, Hurley said that storage routing is getting a lot of attention as an alternative to connecting disparate SANs using the FCIP or iFCP protocol.
"SAN routers help move SANs in the direction of true, routed-meshed networks instead of individual SAN islands," Hurley said. "We expect to see broad adoption of SAN routers in organizations that have multiple fabrics."
More from the Storage Media Group (SearchStorage.com and Storage magazine) on this topic:
News by vendor:
McData router connects multi-vendor SANS
European users dig CNT's director switch
IBM, Cisco spruce up SVC
User endures integration bump with Brocade blade switch
Brocade's 128-port switch drains less power
New EMC software to run on McData switches
Tips and advice:
What type of switches should I use for a pure iSCSI SAN?
Creating an iSCSI SAN using only Ethernet switches
How FC-AL and FC-SW switches are implemented
Building a four-node SAN cluster
What switches to use when implementing an iSCSI SAN
How to scan a SAN
Making sense of new intelligent switch products
Where should storage intelligence reside?
Digital to optical switch conversion
Fast Guide: Fibre Channel basics
Crash Course: iSCSI
Learn more about switches in SAN School
Storage magazine extras:
SAN switch smarts
Disks get switched
This was first published in October 2004