Solaris™ Performance and Tools: DTrace and MDB Techniques for Solaris 10 and OpenSolaris

Chapter 4. Disk Behavior and Analysis

This chapter discusses the key factors used for understanding disk behavior and presents an overview of the analysis tools available.

Terms for Disk Analysis

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 ...