The ABCs of Storage Management, Part II
In Part I of the ABCs of Storage Management, we explored SAN management functions and solutions and the readiness of users to adopt technologies such as automated storage management. In this article, we will discuss real-time infrastructure (RTI) products and storage provisioning, storage virtualization and its role as a management tool, and whether storage virtualization can improve storage utilization.
The concept of storage resource management (SRM) has taken the storage industry by storm because organizations have discovered how it can link them to their employees, customers, and partners across the globe. It has quickly evolved from a simple tool that monitors and reports on storage as a stand-alone component of the enterprise to a set of tools and functions designed to help enterprises better serve their customers.
Some industry experts predict that real-time infrastructure (RTI) products will include storage provisioning. John Lallier, vice president of technology at FalconStor Software, says that enterprises already require automated, policy-based tools that monitor system resources and respond in real-time to changing needs.
Others say that at some point in the future, real-time infrastructure products will include some type of auto-provisioning technology. Ken Barth, president and CEO of Tek-Tools, adds a caveat to that. "I feel that the inclusion of provisioning capabilities will happen and be accepted by customers only when hardware vendors have the overwhelming majority of their products supported with a common interface such as SMI-S [the Storage Management Initiative Specification]," he says.
According to research firm Gartner, storage provisioning is a valuable function because provisioning involves automating a manual task, so it speeds up the provisioning process while also removing operator errors. But Gartner analysts also say that storage provisioning, by itself, is less important than provisioning the whole infrastructure, including storage, to support an application.
The analysts point out that there is a greater emphasis today on server provisioning and higher-level provisioning. Consequently, some industry experts believe that storage provisioning will be a required component of higher-level provisioning products that support real-time infrastructures. In fact, some experts say that current storage provisioning products will have to address their limited depth and platform breadth before integration into higher-level RTI products.
Virtualization Alone Doesn't Improve Utilization: Gartner
One of the more common mantras of many storage vendors is that virtualization actually improves utilization. According to Gartner, storage virtualization alone does not improve storage utilization rates at all.
Ravi Chalaka, vice president of marketing at Maxxan Systems, agrees. "A majority of the storage virtualization solutions sold through 2005 will either be host server-based or storage array controller-based," Chalaka says. "Storage-based virtualization solutions are proprietary by nature, and hence do not allow for better utilization in a heterogeneous environment, and host-based virtualization with direct-attached storage does not use the full benefits of SAN resources for better utilization of disk capacity. As more and more fabrics integrate virtualization services, utilization of all types of storage can be best utilized."
Brendan Kinkade, vice president of marketing for Nexsan Technologies, says that in theory, virtualization should address and improve utilization, but in practice he agrees this is not necessarily the case. "The ability to non-disruptively expand storage pools or capacity as addressed through virtualization is a useful tool, but ultimately it comes down to economics," he says. "Facing the cost of software management against the rapidly decreasing cost of disk storage systems leads many customers to simply add more storage capacity." In other words, explains Kinkade, if it would cost a customer less to buy another 10TB of disk than an additional software package to manage his current 5 TB of storage, then the customer would have to look hard at whether buying a software package makes sense.
Lallier disagrees, and says that improved utilization will result from storage consolidation. "This may come in the form of reducing the amount of over-allocation, or in the form of migrating data so that that characteristics of the storage better match the requirements of the data," he says.
Is Storage Virtualization About Management?
Is storage virtualization really more about management than utilization? Gartner says that storage virtualization is really an enabler of other management functions, including capacity planning and provisioning, but does neither by itself.
Ram Iyler, software manager at Maxxan Systems, believes that higher utilization can be achieved without virtualization by managing resources better. "But the bigger problem that users are trying to solve is the cost of management, and virtualization helps users achieve lower cost of management," he says.
Lallier agrees with Gartner that storage virtualization is a tool for better management, not an end in itself. "You use storage virtualization as a means to provide better disaster recovery, availability, or level of service," he explains.
Barth takes the middle road in the debate. "Virtualization falls into the realm of both management and utilization," says Barth. "On the one hand, virtualization is a tool that can be used as an overlay to help in the management of existing storage in order to stretch resources in times when users are pushing the limits of their infrastructures and are, for example, comfortable being at 80 percent capacity in one area to meet an SLA in another.
"On the other hand," he continues, "when using virtualization in this way, users are actually improving their utilization of existing storage by treating it as a whole unit and keeping departments within their thresholds by allowing the sharing of resources."
Gartner recommends that storage customers invest in storage virtualization based on presumed savings resulting from improvements in storage utilization. Storage virtualization as a component of overall storage management and capacity management may be beneficial, the firm says, but the utilization benefits require SRM tools and, potentially, hardware and an overall understanding of data usage and referring patterns before storage utilization can be improved.