Storage Resource Management

Computerworld - Which employees gobble up the most disk space, and why? What's the best way to partition disk space on a storage-area network (SAN)?

Some savvy information technology professionals won't have any trouble clicking on the answers to those questions. They use data from a storage resource management (SRM) tool to identify and prevent capacity or performance problems and to plan for future storage growth.

Unlike tools that handle storage management tasks like backups, SRM tools provide a central view of either physical storage resources such as RAID systems, tape libraries and SAN switches or of logical storage objects such as volumes, files, users, database tables and I/O.

SRM tools fall into 10 distinct application disciplines: asset management, capacity management, chargeback, configuration management, data/device/media migration, events management and alerts, performance management, policy management, quota/space management and removable media management. Most SRM tools combine several disciplines and were designed to work on specific operating systems such as Windows NT or Unix.

Practically all SRM tools offer two levels of functionality: Monitoring and alerting features (on-screen, e-mail or paging) provide for day-to-day maintenance of storage resources; reporting and trending features provide for long-term maintenance and planning.

			SRM Disciplines at a Glance Asset Management tracks and keeps records of all physical storage hardware on a network. Capacity Management compiles real-time and historical data about physical storage media such as disks and about logical storage resources on a network, such as unused space on specific volumes. Chargeback acts as an accountant for billing end-user departments for used storage capacity and other storage-related network resources. Configuration Management determines how to best arrange current physical network storage such as a disk subsystem and SAN switches. Data/Device/Media Migration enables large amounts of data, such as a data warehouse, to be moved from one system to another. Events Management and Alerts notify systems administrators of errors with storage devices in the network, such as a hard-drive failure, and record all events. Performance Management provides an ongoing view of application, server and subsystem performance, such as excessive I/O from application servers. Policy Management specifies rules or policies for managing hardware, files, users, schedules and media. Quota/Space Management optimizes disk usage by assigning specific space allotments to end users and reclaiming wasted space. Removable Media Management maintains a history of on- and off-site tape, optical storage and other media.

SRM tools usually consist of a service that runs and manages the application from a Web-based central console or graphical-user-interface-based central console, a mechanism for scanning monitored resources, a database that stores collected data from monitored resources and a report generator that can output information in various formats such as Excel spreadsheets or HTML. By supporting Simple Network Management Protocol, an SRM tool can also be administered from network management systems such as Tivoli Storage Network Manager from Tivoli Systems Inc. in Austin, Texas, and Hewlett-Packard Co.'s OpenView.