Storage utilization is a measure of how well the available data storage space in an enterprise is used. There are a number of variables that can be used to determine the storage utilization in a system. The relative priorities assigned to each variable can also affect the utilization figure.
Variables that are sometimes used to determine storage utilization include: (1) the total available storage space in the entire system (raw storage), (2) the time-averaged percentage of raw storage used, (3) the percentage of raw storage used at times of peak demand, (4) the available storage space in each storage volume, (5) the time-averaged percentage of storage used in each volume, (6) the peak-demand percentage of storage used in each volume, (7) the average time required to store or retrieve a file of a given size, (8) the time during peak-demand periods required to store or retrieve a file of a given size, (9) the average size of files stored or retrieved, (10) the ease with which data can be shared among the servers in a network, (11) the microprocessor speed at each server, (12) the random-access memory (RAM) capacity at each server, (13) the speed (in megabits or gigabits per second) with which data is transmitted among different servers, (14) the operating systems used by the servers, and (15) the nature and economic value of data handled by the business.
According to an April 2003 article by Steven Foskett in Storage magazine, several enterprise storage systems were evaluated, and the utilization varied between approximately 30 percent and 60 percent. Limited connectivity was found to be the main reason for poor storage utilization. In addition, many enterprises were using obsolete storage systems. The implementation of a well designed storage area network (SAN) improved utilization dramatically. Several vendors offer storage utilization evaluations, and then recommend solutions.