Oracle Solaris Tunable Parameters Reference Manual


The Oracle Solaris Tunable Parameters Reference Manual provides reference information about Oracle Solaris OS kernel and network tunable parameters. This manual does not provide tunable parameter information about desktop systems or Java environments.

This manual contains information for both SPARC based and x86 based systems.

Note –

This Solaris release supports systems that use the SPARC and x86 families of processor architectures. The supported systems appear in the Solaris 10 Hardware Compatibility List at This document cites any implementation differences between the platform types.

In this document these x86 terms mean the following:

For supported systems, see Solaris 10 Hardware Compatibility List at

Who Should Use This Book

This book is intended for experienced Solaris system administrators who might need to change kernel tunable parameters in certain situations. For guidelines on changing Solaris tunable parameters, refer to Tuning a Solaris System.

How This Book Is Organized

The following table describes the chapters and appendixes in this book.



Chapter 1, Overview of Oracle Solaris System Tuning

An overview of tuning a Solaris system. Also provides a description of the format used in the book to describe the kernel tunables. 

Chapter 2, Oracle Solaris Kernel Tunable Parameters

A description of Solaris kernel tunables such as kernel memory, file system, process size, and paging parameters. 

Chapter 3, NFS Tunable Parameters

A description of NFS tunables such as caching symbolic links, dynamic retransmission, and RPC security parameters. 

Chapter 4, Internet Protocol Suite Tunable Parameters

A description of TCP/IP tunables such as IP forwarding, source routing, and buffer-sizing parameters. 

Chapter 5, Network Cache and Accelerator Tunable Parameters

A description of tunable parameters for the Network Cache and Accelerator (NCA). 

Chapter 6, System Facility Parameters

A description of parameters used to set default values of certain system facilities. Changes are made by modifying files in the /etc/default directory.

Appendix A, Tunable Parameters Change History

A history of parameters that have changed or are now obsolete. 

Appendix B, Revision History for This Manual

A history of this manual's revisions including the current Solaris release. 

Other Resources for Solaris Tuning Information

This table describes other resources for Solaris tuning information.

Tuning Resource 

For More Information 

Online performance tuning information

In-depth technical white papers

Documentation, Support, and Training

See the following web sites for additional resources:

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Oracle Technology Network offers a range of resources related to Oracle software:

Typographic Conventions

The following table describes the typographic conventions that are used in this book.

Table P–1 Typographic Conventions





The names of commands, files, and directories, and onscreen computer output 

Edit your .login file.

Use ls -a to list all files.

machine_name% you have mail.


What you type, contrasted with onscreen computer output 

machine_name% su



Placeholder: replace with a real name or value 

The command to remove a file is rm filename.


Book titles, new terms, and terms to be emphasized 

Read Chapter 6 in the User's Guide.

A cache is a copy that is stored locally.

Do not save the file.

Note: Some emphasized items appear bold online.

Shell Prompts in Command Examples

The following table shows the default UNIX system prompt and superuser prompt for shells that are included in the Oracle Solaris OS. Note that the default system prompt that is displayed in command examples varies, depending on the Oracle Solaris release.

Table P–2 Shell Prompts



Bash shell, Korn shell, and Bourne shell 


Bash shell, Korn shell, and Bourne shell for superuser 


C shell 


C shell for superuser