Assessing storage efficiency
Metrics, assessment process
By Kevin McIsaac
October 15, 2002

To avoid "analysis paralysis" and lengthy benchmarking, ITOs should start with a small and simple set of metrics, such as the following:

Managed storage per administrator: This includes all time spent by staff on all activities in all life-cycle phases required to manage the storage (e.g., deployment, upgrade, provisioning, monitoring, and backup/recovery). The current benchmark for distributed systems is approximately 1.5TB per administrator. ITOs should aim to increase this ratio in sync with their projected storage growth rate.

Cost of storage: This benchmark varies widely depending on the class of storage and decreases over time as storage hardware prices decline. This metric must include all storage related hardware, software, and maintenance costs.

Percentage utilization: This is the percentage of installed storage that is utilized. Distributed systems, with direct-attached storage, can be as low as 30 to 40 percent for small NT servers and 40 to 50 percent for larger Unix servers. Projects (such as storage consolidation) that increase this to more than 70 percent can have a significant impact on the TCO.

Because these metrics are highly dependent on factors such as workload (database versus file and print) or storage SLAs, they should be calculated independently for significantly different of elements of the storage portfolio (e.g., by machine type--mainframe, Unix, or NT--by storage SLA).

Storage assessment process

To calculate these efficiency metrics, ITOs should follow a simple storage assessment process as follows:

Step 1: Develop collection forms by asking a range of staff members for a list of the significant storage tasks undertaken by the storage group. Although this list should be comprehensive, ITOs should avoid overcomplicating collection by adding too many items. A second form is required for listing all the major systems, the total storage capacity, and the used capacity.

Step 2: Collect data by circulating the activity list to all operations staff involved in storage operations. Each member completes this list by recording the number of hours he or she spends on each activity in a typical month. Storage or systems administrators are accountable for recording the total storage capacity and the used capacity used for each system.

Step 3: Analyze results by calculating the metric and reviewing the activities for the largest time sinks (usually backup and recovery) to be targeted in the final step.

Step 4: Transform storage operation by defining and initiating projects that affect these metrics. Typical projects are consolidation and automation of backup and recovery and developing an enterprise storage network. Other projects include process refinement, role consolidation, and staff reduction.

Steps 2 through 4 must be repeated on a regular basis (e.g., six months) to monitor the effect of the transformation projects. Although this process can be performed on most infrastructure components, storage is usually the highest-impact starting point.

Business impact

Although ROI is appropriate for business projects, infrastructure projects are better evaluated on simpler and more direct cost efficiency models.

Bottom line

To constrain a rapidly growing storage budget, ITOs should conduct a storage assessment process that focuses on a few concrete efficiency metrics and then implement projects that transform storage operations to improve these metrics.

SOS: Save on Storage
First published October 3, 2002
By Kevin McIsaac

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Last Modified: March 9, 2008