Why you need storage resource management

Posted on February 01, 2002

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An independent analyst defines SRM and its benefits to IT administrators tasked with strategic storage planning.


Nancy Marrone
Enterprise Storage Group
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By Nancy Marrone

What is storage resource management (SRM)? Look on any of the vendor Websites, and you'll get a different definition. Because it's a hot market, everyone wants to be a player. However, just because an application can look at LUNs on a captive RAID array, it doesn't necessarily mean that it's an SRM application.

At a base level, we classify SRM as one of the five elements of an overall enterprise storage management (ESM) architecture, the others being storage network management, storage virtualization, data management, and storage policy management. Arguably, SRM is the most important element.

SRM is also critical because it enables IT administrators to get an immediate understanding of what storage resources they have, it identifies "space wasters" such as duplicated data and stale data, and it helps administrators understand who is using and creating specific data sets.

IT administrators can't perform strategic storage planning without first understanding their existing environment, which SRM addresses. The cost of SRM is relatively low, so it can sometimes be immediately justified by the "new" capacity it creates for users. Simply put, SRM makes utilization of existing resources far more efficient.

Enterprise storage management

The Enterprise Storage Group has taken elements of existing management models to develop its own version of the Enterprise Storage Management model (ESM). SRM is a piece of ESM and is the focus of this article, but positioning it in the overall scheme is an important first step.

As mentioned previously, there are five key pieces to the ESM model: storage network management, storage resource management, storage virtualization, data management, and storage policy management.

Storage network management is the management of the actual devices that make up the storage network. This includes auto-discovery and mapping of all of the elements in a networked storage environment. Storage network management also includes configuring, managing, and monitoring the health and utilization of those devices.

Storage virtualization is the concept of making all physical storage devices look like one logical pool to the hosts. The advantages of virtualization include more-effective use of resources, easier management of resources, and the ability to move toward a heterogeneous environment (the physical attributes of the storage devices are transparent to the hosts).

Data management includes the backup, recovery, and replication of data and can also include hierarchical storage management (HSM). Data management is the ability to prioritize what data is stored where, based on the need to access or the nature of the application that is using the data. Less frequently used data should be stored on inexpensive storage devices/media. A key factor of data management is determining where the data is at any given time, as well as how to recover it.

Storage policy management is the collection and implementation of user-defined policies within the environment. A centralized policy engine will both push and pull policies from other areas. Ultimately, we expect automation of policies based on rules, but for now, a simple collection process is a start.

Storage policy management is the umbrella that ties all of the applications together. There won't necessarily be a separate storage policy management vendor or solution; rather, each of the solutions will provide policies that will drive automated storage management. SRM applications provide essential usage-based information to tie together all of the benefits of the applications. They are valuable in stand-alone mode, but it will be the sharing of information between SRM and other applications that will provide for true ESM functionality.

SRM defined * As a base definition, SRM is a collection of automated tools that enables administrators to visualize distributed storage resources and provide information on those resources. This allows administrators to make informed decisions about the usage of those resources.

An SRM application allows administrators to understand how storage is being used in their environment. In the current economy, this is increasingly important, because organizations want to make sure they are effectively using existing resources before they make any additional capital purchases. An SRM application not only allows for the visualization of storage usage, but also allows for the control of how storage is used in the future. Users can be assigned space allocation, and the SRM application makes sure that users adhere to those limits.

Features of an SRM application should include

  • A single point of management;
  • Automatic detection of existing and new storage, file systems, volumes, etc., as they are added to the network;
  • Support for all storage devices, regardless of manufacturer;
  • Policy-based management;
  • Asset management and tracking for both hardware and software;
  • Capacity planning and management for more than spindles;
  • Integration with media management architectures;
  • The ability to keep track of multiple copies of the same data, in different places;
  • Flagging of events up to the network management framework;
  • Performance management;
  • Ability to locate stale data; and
  • Generation of easy-to-read reports.

Other functions might include

  • The SRM application should not be limited to a particular operating system;
  • SRM should deal with any storage element, regardless of how it is attached (SAN, NAS, direct-attached); and
  • The SRM application should do more than just report on all of the above. Administrators will want to do something with the information based on the policies they set.

SRM today

Presently, there are about a dozen SRM vendors with products that are valuable in either stand-alone mode or as part of a larger ESM solution. The biggest reasons users want to use SRM today are to understand their existing asset allocation, determine usage patterns, drive quota management, and instill best practice policies around storage use.

SRM applications are instrumental in designing a storage network and can help administrators plan for future resource allocations. SRM can also free up resources (being used for mp3 files, games, or antiquated files) and ensure that users don't hog space through quota-management techniques.

These applications give a company the ability to fully understand how its storage assets are being used. SRM software reports on which assets are on the network, how much space is (or is not) being used, who is using that space, and how often it is being used.

SRM + ESM

SRM applications can assist administrators in making informed decisions about the use of their storage resources. However, there is a greater potential for SRM software if it is combined with management applications in the ESM model.

For instance, if a company buys into the concept of virtualizing all of its storage assets, how does it know what is being used, and by whom? Should the company virtualize before it really knows how its storage is being used? No. The best approach is to run an SRM application to understand the current situation and then create the virtual pool of storage. Rules, quotas, and threshold levels can be set after the administrator has a thorough understanding of how the assets are currently used.

SRM applications can also be instrumental in assisting with data management. An SRM application can determine where data is located, what users (or groups) the data is associated with, and how long that data has been on a particular storage device. This information is key to an administrator who determines when and if data should be moved, flushed, backed up, etc.

Integrating an SRM application into a virtualization or data management application enables policy-based management. Imagine an SRM application alarming a virtualization application when a volume is getting full. The virtualization engine will then shut off access to that volume, transparently to users. Or, an SRM application could trigger a data management application such as backup when data on a particular array has been there for 90 days, and the data management application automatically archives it.

This process brings us back to auto-provisioning of a storage network. Say a user needs an additional 3GB of storage for a particular application. The policy engine would allow for an administrator to enter in some parameters (e.g., 3GB, attached to Unix host x), and the management applications would do the rest.

If the capabilities of SRM and storage network management were integrated, resource use on the network could be monitored, excess volumes could be located, and the devices could be automatically provisioned to hosts based on defined policies. Tying in virtualization capabilities would allow for more flexibility in the actual physical provisioning.

The players

We split the players into two groups: vendors with stand-alone SRM applications, and vendors that have an SRM component as part of a larger storage network management solution.

Many of the stand-alone application vendors are partnering with vendors that have applications in the other areas in order to reach the goal of policy-based management and auto-provisioning.

Vendors with stand-alone SRM applications include Astrum Software, NTP Software, Sun (via its acquisition of HighGround), Precise Software (which acquired WQuinn), TeraCloud, and TrelliSoft.

Those with an SRM component in their enterprise storage management offerings include BMC Software, Computer Associates, Hewlett-Packard, IBM/Tivoli, Compaq (which resells HighGround's SRM), EMC, and Veritas.


Nancy Marrone is a senior analyst with the Enterprise Storage Group (www.enterprisestoragegroup.com) in Milford, MA.

Originally published on .

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