Overview of Solaris System Tuning
This section provides overview information about the format of the tuning information in this manual. It also describes the different ways to tune a Solaris system.
What's New in Solaris System Tuning?
The following table lists important new tunable parameters or changes in the Solaris 9 release.
Feature | For More Information |
|---|---|
Removal of the priority_paging and cachefree parameters | |
Network Cache and Accelerator (NCA) parameters | Chapter 5, Network Cache and Accelerator (NCA) Tunable Parameters |
New system facility parameters for inetd, keyserv, syslogd, and rpc.nisd | Chapter 5, Network Cache and Accelerator (NCA) Tunable Parameters |
The following parameters are new or changed but might not be identified as changed in this book's appendices. For more information, see the specific parameter information in the main topic chapter:
pages_pp_maximum
ufs_LW and ufs_HW
md_mirror:md_resync_bufsz (new to the Solaris release)
tcp_deferred_ack_interval
tcp_local_dack_interval (new)
tcp_deferred_acks_max
tcp_local_dacks_max (new)
tcp_xmit_hiwat
tcp_recv_hiwat
tcp_time_wait_interval
tcp_ecn_permitted (new)
Tuning a Solaris System
Solaris is a multi-threaded, scalable UNIX™ operating environment running on SPARC and Intel processors. It is self-adjusting to system load and demands minimal tuning. In some cases, however, tuning is necessary. This guide provides details about the officially supported kernel tuning options available for the Solaris environment.
The Solaris kernel is composed of a core portion, which is always loaded, and a number of loadable modules that are loaded as references are made to them. Many of the variables referred to in the kernel portion of this guide are in the core portion, but a few are located in loadable modules.
A key consideration in system tuning is that setting various system variables is often the least effective thing that can be done to improve performance. Changing the behavior of the application is generally the most effective tuning aid available. Adding more physical memory and balancing disk I/O patterns are also useful. In a few rare cases, changing one of the variables described in this guide will have a substantial effect on system performance.
Another thing to remember is that one system's /etc/system settings might not be applicable, either wholly or in part, to another environment. Carefully consider the values in the file with respect to the environment in which they will be applied. Make sure that you understand the behavior of a system before attempting to apply changes to the system variables described here.
Caution - The variables described here and their meanings can and do
change from release to release. A release is either a Solaris Update release
or a new version such as Solaris 9. Publication of these variables and their
description does not preclude changes to the variables and descriptions without
notice.
Tuning Format
The format for the description of each variable follows:
Variable-Name
Description
Data Type
Default
Units
Range
Dynamic?
Validation
Implicit
When to Change
Commitment Level
Change History