Goodbye to old, hello to the new SRM confusion: enterprise storage resource management fulfills the promise.

Storage infrastructures are increasingly distributed and complex, with large organizations implementing a variety of storage topologies including NAS, SAN and DAS, along with a range of network fabric types. There is a strong value in aggregating this distributed picture through a single, centralized console, which IT professionals can use to manage their storage resources. Enterprise Storage Resource Management expands on basic SRM and adds provisioning and automation tools to the mix.

SRM Evolution

Basic SRM, which ESRM retains, automates the discovery process of networked storage resources, observes threshold policies ruling capacity shortages and excess usage, and reports on storage consumable rates. The market usually refers to these features as discovery, monitoring/alerting, reporting and forecasting (See Figure 1).

For example, one of SRM's primary functions is collecting and reporting statistics on capacity usage and growth trends. ESRM expands that feature, allowing IT to identify not only disk usage and file types, but also track usage and growth by application. This in turn allows companies to track application usage as well as key storage consumers. Once IT knows that the company's CRM is taking up huge amounts of storage volume, and that the Sales division is its major user, IT is in a position to justify Sales' request for more storage space. If, however, a payroll program is relatively static, IT can question Accounting's yearend demand for an increased storage budget. And because ESRM works across a variety of storage deployments and over remote connections, it does a better job at identifying who's taking up your storage resources across the enterprise, not just on your SAN. Dan Hoffmann, BMC's director of enterprise storage management, discusses ESRM in the context of departmental chargebacks. Hoffman said a bout IT, "What they really want to do is have a piece of paper at budget time when a department comes to request space. They want to associate a cost with it." Hoffman added that they also want to come back and say, "You guys are using one quarter of company storage, and this is how much it costs."

ESRM's wide reporting capabilities also help prove Return On Investment (ROI) by giving senior management a handle on the storage administrator's impact on the company. It also gives a fairer picture of Total Cost of Ownership (TCO) by allowing IT departments to include all the elements of storage costs beyond the initial investment and deployment. Ken Steinhardt, EMC's director of technology analysis noted about ESRM, "This is not only a key area for customers right now, but especially in the current economic environment customers are challenged to do even more with decreasing or flat budgets."

For all its promise, ESRM will need to prove itself in a way SRM could not. SRM was supposed to solve the capacity-planning problem, but sales never met the analysts' forecasts. The reason: No one anticipated how rapidly the cost of hardware would drop, which made it far easier to just add storage than to manage it. Also, the first SRM products returned only limited data. The hope for ESRM is that it will return useful information such as reporting that a payroll system is growing 50% every six months, or that manufacturing data is taking up most storage resources, or that a database application's Quality Of Service (QOS) requirement will require high performance storage equipment.

Chris Van Wagoner, director of marketing at Comm Vault, agreed that SRM originally held a passive role but that ESRM offers a much more active one. ESRM takes SRM's basic discovery, monitoring and reporting functions and combines them with deeper logical and physical views of physical storage infrastructures. This adds automation and policy-based management into the mix. SRM used to concentrate exclusively on physical views of specific storage resources, but ESRM also offers the storage infrastructure behind the drives, as well as identifying users and applications from stored data. This is useful because as storage networks grew, businesses increasingly needed to know not only the capacity and health of individual drives, but also dependencies and paths throughout the storage infrastructure.

Van Wagoner believes that near future development will increasingly track and link to applications. For example, an SRM product may report the ages of individual files and allow the IT administrator to institute automatic migration policies. But what if an older file is automatically migrated or archived by a certain set of pointers, but it turns out that a critical application needs it? ESRM would be able to tie these critical files to their respective applications, and operate migration policies accordingly. Further along in the development cycle, vendors might expand ESRM beyond single copies of online data to entire data life cycles. ESRM would manage not only primary data, but also availability copies such as replications, snapshots, archived and backed-up files.

Increasingly ESRM is expanding from the SAN to the data center and beyond to remote storage management. This is not due to any new remote capability: SRM could always work over any kind of TCP/IP network link. But since basic SRM tools could not actually affect changes, it did little good to run it remotely. For example, a storage administrator based in Detroit could run a storage report on a Dallas division, but if the SRM reported that a disk drive was running out of space there is nothing the Detroit-based administrator could do. But ESRM's active features might improve that picture. Van Wagoner said, "The active elements that ESRM had been defined around make it better as an enterprise tool because it can be deployed remotely. The whole dynamic portion of ESRM means you can now use it for configuration management, where you can actually do some work. That will impact provisioning, failover, monitoring, status--so that if a pathway goes I'll be able to record that and reboot it."

Active Management

Veritas' ServPoint marketing manager Ruth Colombo said, "SRM involves active management of your critical assets that really involve those critical applications. File reporting is not really active management, and that's also usually not something that happens in real time. You're analyzing historical data. Enterprise SRM requires real-time monitoring and policy-based management of critical resources in your storage infrastructure."

SRM already visualizes storage devices in network topology maps, but cannot logically associate servers with storage devices nor track logical paths between the two. With no simple way to understand paths and dependencies, storage administrators often set up critical systems with single points of failure. Karen Dutch, InterSAN's director of marketing said, "What you really need now is a birds-eye view, having a server perspective view but also sitting outside the whole storage infrastructure."

According to Dutch, ESRM should be concerned with path management--overlaying a logical layer on top of device-level physical management. ESRM would manage paths between servers and storage and all other fabric elements, including connections, devices, dependencies, structures, and physical and virtual volumes. A path-management perspective allows storage administrators to identify critical applications and to establish redundant paths. In the event of a path failure, processes will still run successfully over redundant paths.

Path-centered management is particularly important in large SANs, whose storage administrators struggle to manually manage hundreds of terabytes of data accessing hundreds, even thousands of ports throughout multiple locations. ESRM is immensely valuable if it can automatically take corrective action to route around problem areas. Dutch added, "One of the other things that we find the bigger customers want as part of their overall management solutions, is all the discovery and monitoring you have to do. You have to base your automation on policy, because policy allows the user to customize. operations with their own operational procedures. Automation goes hand in glove with policy."

If SRM has meant discovery, monitoring, and reporting, modern SRM adds provisioning and automation, particularly in multi-vendor environments. EMC's Steinhardt suggests that the provisioning and automation elements are the breakthroughs, since automation is key to mitigating risk factors involved in provisioning storage. He notes that provisioning is fraught with peril in larger storage area networks, where risk factors include performing sophisticated and demanding procedures such as zoning and LUN masking. Presently there are four ways that storage administrators can provision storage:

* Command line interface: Long and cumbersome, it requires detailed knowledge of provisioning procedures. Experienced storage administrators are familiar with the commands, but the process is labor-intensive and time-consuming.

* GUI: An interface that visually represents the storage network infrastructure. The visuals help administrators to provision storage, but still require detailed knowledge in the administrator's part. It is prone to serious human error because less experienced administrators are more likely to tackle the GUI than command line interfaces.

* Wizard: A wizard suggests procedures and carries out commands via a visual network topology map. This is an intensive process, though not as risky as the GUI nor as time-consuming as the command line interface.

* Automated provisioning tool: ESRM offers automated provisioning tools more advanced than the wizards. For example, EMC's ARM allows administrators to prioritize storage by levels. This allows them to assign redundant paths and/or high performance bandwidth to critical applications while assigning less expensive resources to lower-level applications.

Still, a majority of IT departments report that they aren't looking for lights-out management (a fully-automated provisioning process), but prefer wizards or assisted automation. Veritas' Colombo said, "In my experience, many customers are not ready for fully-automated Storage Management, but what they are ready for is assisted Storage Management." In this scenario, ESRM management software would assist the IT administrator by presenting decision points during the provisioning process.

SRM still generates a healthy revenue stream for its developers, but the first generation products never hit the analysts' expectations. At the time SRM was introduced, storage hardware prices started falling fast and hard. This made it far easier for companies to add more storage rather than improve storage management. But now that managing storage environments have become critical, ESRM may end up fulfilling the promise SRM did not. Carolyn DiCenzo, chief analyst at Gartner said in a research note, "The storage-management software market is in a period of transition as the focus on improved device management provides the necessary devices and operating systems... As storage infrastructure and device-management products mature, the focus will shift to SRM and providing infrastructure for a higher level of software tools that will manage across the richer tools that customers have been waiting for."

Figure 1


Discovery    Identifies and characterizes
             storage subsystems, switches and
             servers on the network.

Monitoring/  Monitors status of storage devices,
Alerting     issuing alerts when device fails or
             when performance or capacity
             thresholds are breached.

Reporting    Reports on utilization rates including
             under-utilized capacity, peak usage and
             growth patterns for users, servers and
             file systems.

Forecasting  Provides trend analysis to identify
             future storage needs and purchase
             timing. Forecasting tracks linear growth
             and often uses statistical probability
             models.