Keeping track of storage
- By Alan Radding
- Aug 30, 2004
Managing an information technology storage environment can be, to say the least, challenging. As users clamor for more space to store files and data across
numerous devices, many IT managers find it difficult to keep track of how much storage capacity is available, how it is allocated and how much is actually used.
These are the simple problems. The tougher questions involve ascertaining how recently or how often a file has been accessed or how many duplicates of a given dataset are stored. Without answers to those questions, IT managers cannot wisely plan and manage their storage
To address such issues, IT staff members typically review log files on many servers and manually input the findings into spreadsheets. It is a slow, tedious, costly process that consumes staff resources at a time when government agencies are facing constrained IT budgets.
However, a set of products centered on a concept called storage resource management (SRM) could give IT managers some much-needed relief. SRM consists of capabilities that help managers identify their storage needs and track usage for efficient utilization, storage planning and capacity management.
According to Mike Karp, an analyst at Enterprise Management Associates Inc., a full set of SRM capabilities includes: storage capacity discovery, topology mapping, reporting, event management, path management, dependency analysis, capacity management, organizational knowledge, performance management, security management and trend analysis. SRM capabilities also may include chargeback and storage automation.
The driving force behind SRM today is "the need to get the most value out of your existing storage hardware," Karp said. SRM addresses this need by identifying an organization's storage capacity and how it is being used.
Given the difficulty of identifying storage capacity and utilization without SRM, IT managers often find it easier to buy more storage capacity even though they have excess capacity elsewhere. If they knew what was available and how it was being used or not used, as the case may be they could put any unused capacity to work instead of buying more.
SRM also helps IT managers free disk space by identifying data that doesn't need to be stored at all, such as unnecessary duplicates, unneeded data or data that should never have been stored in the first place, such as personal JPG or MP3 files.
"We expect to get a 20 percent increase in storage capacity just from implementing Computer Associates [International Inc.'s] BrightStor SRM," reports Glenn Exline, manager of advanced technologies at the Air Force's 45th Space Wing, Cape Canaveral, Fla.
The increase comes painlessly. "We run reports and see how many of the stored files are owned by nobody by people whose accounts have been deleted," he said. Those files can be moved off primary storage immediately and are often deleted altogether.
Exline also uses the SRM tool to find files that have not been accessed for two years or are duplicates. "If they haven't been used for two years, we move them to low-cost [Advanced Technology Attachment] storage arrays rather than our primary Fibre Channel arrays," he said. He deletes duplicate files.
SRM encompasses a wide range of capabilities. IT managers in government agencies do not have to buy or implement every feature to begin getting a payback from the technology. As officials at the 45th Space Wing discovered, you can start getting results from just the core SRM capabilities. Such features include discovery, reporting and monitoring, said Barry Ader, director of software products at EMC Corp.
Through discovery, the SRM tool identifies all the storage capacity that can be accessed via the corporate networks wherever it may reside and regardless of the platform. Administrators run the discovery function as soon as the SRM tool is installed and often immediately discover unused storage capacity.
Reporting allows officials to analyze storage usage more closely. Exline, for
example, runs reports to identify duplicate files or long-dormant files. Monitoring enables managers to follow the performance of an organization's applications to ensure that they are getting the storage they need to meet service-level requirements.
But one doesn't have to implement everything to earn benefits.
Officials at the California Department of Health Services' Genetic Disease Branch, turned to Veritas Software Corp.'s Quota Advisor, a component of the company's larger Storage Central SRM product, when they found the group was running out of disk capacity.
Using Quota Advisor, branch officials were able to assign and enforce storage quotas for users for the first time. When users exceed their quotas, they are warned to delete unnecessary files. "Now we are able to keep certain types of files completely off the storage, and we have avoided having to do drastic data deletion," said Deborah Moorer, a Microsoft Corp. Windows NT administrator at the branch.
Once SRM basic functionality is implemented, administrators can add
advanced SRM features as needed. These
include path management, which is
particularly useful when there is a storage-area network, a high-speed subnetwork of shared storage devices.
Path management identifies and monitors the use of various network infrastructure elements such as switches, ports and host bus adapters. Capacity management draws on current and past usage to predict the rate of storage growth. It enables managers to intelligently add storage capacity. For internal billing purposes, chargeback tracks the amount of storage consumed by individual users, workgroups or departments.
Finally, there is the question of automation. Until recently, SRM products generally lacked the ability to automate complex functions such as provisioning, which is the process of assigning storage. The SRM tool could identify when a particular application exceeded a threshold but couldn't automatically add more
Now vendors are including automation capabilities as part of their SRM packages, said Dennis Martin, analyst at the Evaluator Group. "The vendors will offer different levels of automation depending on the customer's concerns about control," he said.
The combination of SRM and automation lays the foundation for information life cycle management (ILM), in which data is automatically moved to the most cost-effective storage based on various criteria such as age or frequency of access.
"We want to get to ILM, which will let us efficiently manage vital data," Exline said. Getting there begins with SRM.
Radding is a freelance journalist based in Newton, Mass. He can be reached at firstname.lastname@example.org.