Theory and Practice in Storage Networking

The theory and value proposition behind storage networking and Storage Resource Management (SRM) technology is well known. By putting storage on a network, you can more efficiently manage your storage resources rather than haphazardly add more capacity every time an application generates an excessive amount of data. So, when disk-space utilization rates climb, rather than add more capacity when rates reach 30 to 40 percent, if you manage resources, disk space utilization could reach perhaps the 60 to 80 percent mark or higher before you need to add new hardware.

On a well-managed storage network, administrators can more effectively control challenging storage-related tasks, including backing up, restoring files, and controlling the entire data life cycle. Administrators can store valuable, time-sensitive, and frequently accessed data on more robust storage devices and migrate lower-value and rarely accessed data to more cost-effective devices. According to the storage-management theory, a company's storage could conceptually appear to administrators as one big pool that becomes filled through the application of effective, automated policies and efficient provisioning.

But theory and practice can look very different. Panelists discussing storage at the FOSE 2003 government technology conference in Washington, D.C., 2 weeks ago discussed at least five cultural or technical barriers that have deterred enterprises from integrating their storage resources into one all-encompassing storage network. The biggest barrier is fear of making mistakes. Storage administrators worry that if they misconfigure a device, they'll lose crucial data. Storage administrators also worry that they might establish a new storage management zone and the entire Storage Area Network (SAN) will stop working as a result. Keeping UNIX resources on one storage network and Windows resources on a separate network is a risk-management strategy that reduces the chances that a major mistake or malfunction will occur.

Another technical barrier deterring enterprises from consolidating resources is that different kinds of applications often run on different platforms. For example, mission-critical applications commonly run in UNIX or mainframe environments, whereas a broad range of other applications run on Windows. Given the different needs and challenges these applications present, administrators are hesitant to commingle the storage resources for applications of differing value. Indeed, administrators want to segregate, not integrate, the infrastructure for such applications.

A third constraint is security. To put sensitive data on a network leaves the data more vulnerable. Problems surrounding storage security still exist. Many common aspects of network security, such as role-based access, authorization, authentication, and auditing and tracking, need to be reworked for appropriate application to storage networking. Further, security processes often work against a key feature of storage networking—ease of use.

The security problem becomes more complex: Not only does a storage network open points of vulnerability but storage security is only one aspect of an overall security infrastructure. The storage security layer has to be integrated with the network and application layers, which is tricky business.

The fourth barrier to the emergence of enterprisewide, comprehensive storage is storage administrators of large data centers' desire to lock down and secure their data. These administrators aren't accustomed to or comfortable with providing access to their companies' most valuable information assets. They're also uncomfortable with storing crucial data on the edge of the network, so achieving the right balance between access and control can be difficult.

The last constraint preventing storage administrators from moving toward wider SANs is the emergence of new technology. Rather than automating processes already in place, administrators need to rethink their objectives to take into account the new technologies at their disposal.

Barriers don't mean that the theory of storage networks and storage resource management is wrong. Barriers simply symbolize that resolving the difference between the promise of the possible and the reality of the practical takes time and perseverance.