In existing database environments, the first step to determine data storage requirements is to take an inventory of your storage needs. The types of storage are:
Performance oriented — Database or portions of databases, before-image (BI) areas, after-image (AI) areas
Archival — Historical data, backups
Sequential or random — Data entry and report generation, or spot queries
Performance oriented — Database or portions of databases, before-image (BI) areas, after-image (AI) areas