The Search for Sentient SANs Page 3
Storage Virtualization Adrift in the SAN Sea
Currently, storage virtualization technology is adrift in the SAN space. Vendors of host software such as VERITAS argue that storage virtualization is best anchored as a server-based technology. This provides independence from both the storage arrays and the SAN interconnect type.
Virtualization appliance vendors such as FalconStor, on the other hand, claim that virtualization should sit on the storage network, and so are creating black boxes that simply attach to the SAN, intercepting server requests and redirecting data to dispersed storage resources. This offloads both the host systems and facilitates heterogeneous storage environments.
Meanwhile, storage array manufacturers such as EMC, HDS, and XIOtech are either promoting their own flavors of array-based virtualization or allying themselves with other solutions that they can control. Array-based virtualization tends to be more tightly integrated with RAID and other storage functions, but these are largely single-vendor solutions.
And finally, fabric switch vendors such as Cisco and Brocade are developing switch-based virtualization engines, highlighting the central position of switches in a SAN and the ability of switches to redirect between any storage targets and any servers.
All of these individual solutions have their respective merits and demerits, but collectively they indicate that SANs are becoming more intelligent in terms of automating and simplifying complex storage processes. Whether that intelligence resides in hosts, in appliances, in storage targets, within SAN switches, or is distributed throughout various SAN components, the net result is that fewer administrators will be required to manage additional storage capacity more efficiently and more cost-effectively.
The end-user value of SAN technology in general, which is already well-established in the market, will be raised to a more productive level once the complexity of SANs has been hidden from view. This in turn expands the market for SAN technology, enabling it to penetrate the vast small and medium business arena which thus far has been hesitant to adopt SANs.