Release 10.1A: OpenEdge Getting Started:
Database Essentials

Disk capacity

The disk system is the most important resource for a database. Since it is the only moving part in a computer, it is also the most prone to failure. Reliability aside, a disk is the slowest resource on a host-based system, and it is the point where all data resides.

There are three overall goals for a database administrator in terms of disk resources. They are:

Quantity — Have enough disk space to store what you need.
Reliability — Have reliable disks so your data will remain available to users.
Performance — Have the correct number and maximum speed for your disks to meet your throughput needs.

These goals sound simple, but it is not always easy to plan for growth or to know what hardware is both reliable and appropriate to meet your needs. With these goals in mind, this section examines the problems that might present roadblocks to fulfilling each of these goals.