By Lisa Coleman
A recent survey of 100 IT professionals from a variety of companies, including Global 2000 corporations and mid-sized businesses, indicates that storage area networks (SANs) have become "mainstream," with at least one SAN deployed in four out of five of the surveyed companies, according to IT consulting firm Ashton, Metzler & Associates, in Sanibel, FL.
Jim Metzler, vice president at Ashton, Metzler & Associates, says that what's surprising in the survey results is the rapid growth of SANs relative to other storage technologies. For example, currently less than one out of five companies uses a SAN to support 60% or more of its storage requirements. However, within a year more than half of the companies will use a SAN to support 60% or more of their storage requirements.
"Put another way, SANs will soon be the dominant storage architecture," Metzler says.
For those companies using SANs, slightly more than 36% have deployed 11 or more Fibre Channel switches, and 40% of those switches are director-class, according to the survey (see figures).
The trend toward storage, server, and data-center consolidation is in large part driving SAN adoption, claims Metzler.
The survey also shows that SANs are increasingly being used to host "mission-critical" applications such as enterprise resource planning (ERP), customer relationship management (CRM), and enterprise e-mail. Approximately 78% of the respondents run ERP applications on SANs, 77% run CRM on SANs, and 57% run enterprise e-mail on SANs.
With a high percentage of applications running on SANs, application "brownouts" can have a significant impact, according to Metzler. An application brownout occurs when, for example, one or more applications perform much slower than is typical.
Among the survey respondents, application brownouts occurred regularly. About 70% of the companies reported having an application brownout at least once a month. Meanwhile, about half of the respondents indicated that they did not have a "good handle" on what caused the brownout.
"Storage professionals who were interviewed for this study pointed out that although the current technology does not allow validation, there is a nagging belief that issues in the SAN often lead to application brownouts," says Metzler.
For ERP applications running on SANs, about 56% of the survey respondents never experienced a brownout, but 27% experienced brownouts at least once a month. The percentages for brownouts were higher for CRM and e-mail applications. For those respondents running e-mail applications on SANs, approximately 28% reported a brownout at least once a month and another 16% reported a brownout at least once a week.
The impact of an application brownout was cited as "significant" or "very significant" for 30% of the respondents. However, the survey does not conclude that SANs are necessarily the primary cause of brownouts.
Overall, the survey concludes that SANs are evolving toward edge-core designs, where most of the host and storage devices are attached to edge switches. However, less than 40% of the respondents said they would use this guideline today to add a new device. Approximately 39% said they would follow edge-core guidelines if they needed to add a new device one year from now.
The Ashton, Metzler survey results are in a report called "SANs and the Applications They Support." For more information, go to www.ashtonmetzler.com.