Unix® System Management Primer Plus

Gauging Storage Performance and Capacity

The performance of storage devices, hard disks in particular, is vital to the performance of a system because absolutely everything is stored there, including the operating system, applications, and application data. Swap space is located on disk as well—a poorly performing swap partition can severely degrade the performance of a system, especially in low-memory conditions.

To fully understand how to assess and optimize storage performance and capacity, you must first understand certain basic storage concepts and terms, including storage capacity, disk architecture, bandwidth, latency, sequential and random access, block and character I/O, and inodes. After defining each of these items, the following sections ...