This chapter discusses the key factors used for understanding disk behavior and presents an overview of the analysis tools available.
The following terms are related to disk analysis; the list also summarizes topics covered in this section.
Environment. The first step in disk analysis is to know what the disks are—single disks or a storage array—and what their expected workload is: random, sequential, or otherwise.
Utilization. The percent busy value from
iostat -x serves as a utilization value for disk devices. The calculation behind it is based on the time a device spends active. It is a useful starting point for understanding disk usage.
Saturation. The average wait queue length from ...