Mike Taylor's reaction to the idea of storage service level agreements (SLAs) is typical: They haven't hit his high-priority list yet, but he suspects that will change fairly quickly. "We really don't have formalized service levels for storage at this point," says Taylor, a storage administrator at Capital Blue Cross in Harrisburg, PA. "But I do see them coming."
It's an interesting conundrum. The people who measure for SLA compliance are the same people being held accountable for them. Most experts say, however, that the system works if both the user side and the storage side are working towards the common goal of driving down costs. For example, if storage services operate on a chargeback basis, storage managers are probably working towards specific cost cutting goals. It's therefore in their best interest to meet the SLAs, says Mark Friedman, the vice president of storage technology at DataCore in Ft. Lauderdale, FL. "You enforce SLAs best at the level of the cash register," he says.
Jean Banco, a product manager at Fujitsu Softek in Sunnyvale, CA, says the buck stops at the application manager. Here's why: "The application manager generally is the one to set service levels for the storage manager on the automated tools," she says. "They set up the storage requirements, the performance requirements, recoverability, security--the business-centric side of things." It's then the storage manager's responsibility to map those requirements to the physical storage environment, and the application manager is the one who tracks compliance.SLAs that measure the wrong things Router availability, storage availability and backup: All of these things are commonly found in SLAs, but storage managers who use them as the basis for SLAs are using the wrong yardstick, says Raymond Paquet, an analyst at Gartner Group. "At the end of the day, an SLA is composed of three words, and 90% of IS groups forget the first one," he says. "Most people define a metric and think that's the definition of the service. That's wrong. The first part is defining the service." The bottom line is storage services should be things that are meaningful and impact the business. For example, "Storage availability isn't a service," he says. "As a business user, I don't care if storage is available or not. I want the application to be up." Paquet advises IS groups to continue to measure and monitor such storage benchmarks, but only as internal measures. "I'd use them to hold the storage management group accountable within IS," he says. "The availability of underlying components are interesting to IT, but not to the business." So what would Paquet build storage SLAs around? The things that business people will come directly in contact with, he says: recovery and provisioning. Richard Scannell, the VP of corporate development and strategy at GlassHouse Technologies, Inc., Framingham, MA, says SLAs are frequently unenforceable because storage managers don't implement policies and procedures spelling out how to accomplish the SLA. "No technology by itself can produce SLA compliance. It's how it's used by people, and a big problem is not defining processes and procedures that support SLA compliance," he says. The problem, according to Scannell, is that it's difficult to define processes--"to say, here are the things to measure, and here's how to translate them into capital, expense and human requirements. As a result, the SLA is the equivalent of giving the CIO enough rope to hang himself with." Mapping an SLA to reality Every line business manager will be the first to tell you their application is absolutely mission critical, but the truth is there will always be some systems that are more vital than others. But many application SLAs don't take that into account, and instead assign service levels that are overly high for a given application. The trick is to find a way to get users to agree to lesser levels of service. Like Wendt, Scannell suggests to make the conversation about money. "Pass some of the responsibility back to the customer," he says. Once a SLA is agreed upon then the fun begins: measuring its compliance. There's a bunch of SRM tools on the market that do a good job of collecting data from individual storage devices. However, Gartner's Paquet says, "There's no way to aggregate the data," adding, "Without a common data structure, how do you correlate the data?" Wendt agrees, saying the heterogeneous technology environment of open systems storage makes it almost impossible to find a tool that will measure service level adherence across the enterprise. Wendt envisions software running a management console that lets him build customized data collection metrics on various aspects of the storage infrastructure. "I could have a script running in the background that would tell me when I was about to go out of the window of acceptance on a service level, but right now I don't have any automated way of collecting this data," he says. "A lot of measurement is still seat-of-the-pants, and that's no way to measure an SLA." Aberdeen's Tanner says, "Tools managing things like storage, network resources, file services, database services are extraordinarily complicated, and there's no tool that does it all. The more sophisticated they are, the fewer vendors they work with." He says companies on the leading edge of storage SLAs have built their own tools. Some of the better tools are coming from SSPs, many of which are struggling financially. According to Tanner, "SSPs have discovered that companies don't want to outsource storage, but they all have developed software that will let companies manage storage internally like an SSP." This includes being able to measure SLA adherence. Sooner or later, most companies are moving to storage SLAs. First Data's Wendt says, "SLAs are definitely coming, and I need to start thinking about this."
About the author: Carol Hildebrand is a freelance writer who regularly covers storage and management topics.