Solaris System Tuning

Here is Sun's guide to tuning Solaris:
http://docs.sun.com/app/docs/doc/806-7009/6jftnqsiu?a=view

The most important thing to remember here is:

Make a copy of /etc/system before modifying it so you can easily recover from incorrect value
# cp /etc/system /etc/system.good

If a value entered in /etc/system causes the system to become unbootable, you can recover with the following command:
# boot -a

his command causes the system to ask for the name of various files used in the boot process. Press the carriage return to accept the default values until the name of the /etc/system file is requested. When the Name of system file [/etc/system]: prompt is displayed, enter the name of the good /etc/system file or /dev/null.

If /dev/null is entered, this path causes the system to attempt to read from /dev/null for its configuration information and because it is empty, the system uses the default values. After the system is booted, the /etc/system file can be corrected.

The guide will explain the different tunables, how to check performance, and when to change the settings.