About This Manual

This manual contains information about configuring Compaq Tru64 UNIX (formerly DIGITAL UNIX) for high performance and high availability. This manual also describes how to tune systems to improve performance.

For Tru64 UNIX, it is recommended that you use the graphical user interface (GUI) for system administration. This GUI is presented by SysMan, an application that is loaded by default when the Common Desktop Environment (CDE) software is loaded on your system. The SysMan applications are available in the Application Manager, which you can access from the CDE Front Panel.

Audience

This manual is intended for system administrators who are responsible for managing a Tru64 UNIX operating system. Administrators should have an in-depth knowledge of their applications and users, in addition to operating system concepts, commands, and utilities. Such an understanding is crucial to successfully tuning a system for better performance.

New and Changed Features

Additions and changes that have been made to the manual for this version of Tru64 UNIX include the following:

• This manual describes only kernel subsystem attributes that can be used to improve system performance. All kernel subsystem attributes are documented in the reference pages. See sys_attrs(5) for more information.

• Kernel subsystem attributes use only underscores instead of combinations of dashes and underscores.

• Section 4.1 describes the steps that you can follow to configure and tune high-performance and high-availability systems.

• Tru64 UNIX is able to satisfy page faults by reclaiming pages from the free page list. This improves virtual memory and Unified Buffer Cache (UBC) performance.

• The vm_perf data structure and other data structures require you to specify a processor number.

• You can specify swap devices by using the vm subsystem attribute swapdevice. See Section 6.2 for more information.

• LSM provides RAID 5 and hot spare support. See Section 8.4 for more information.

• LSM block-change logging (BCL) has been replaced with dirty-region logging (DRL), which can improve the recovery time of mirrored volumes after a system failure.

• AdvFS supports direct I/O, which can significantly improve disk I/O throughput for applications that read or write data only once and do not reuse the data. See Section 9.3.4.7 for more information.

• Smooth sync functionality improves AdvFS asynchronous I/O performance by preventing I/O spikes caused by the update daemon, increasing the chance of a buffer cache hit, and improving the consolidation of I/O requests. See Section 9.3.6.5 for more information.

• There are two new AdvFS subsystem attributes, AdvfsMinFreeAccess and AdvfsMaxFreeAccess, which control the allocation of AdvFS access structures. See Section 9.3.6.3 for more information.

• It is no longer necessary to preallocate space for the AdvFS bitmap metadata table (BMT) or increase the number of pages by which the BMT extent size grows. The operating system performs this function automatically. See Section 9.3.5.6 for more information.

• You can modify the UFS block size by using the newfs command. See Section 9.4.1.1 for more information.

Organization

This manual consists of eleven chapters and a glossary:

Related Documents

The System Administration manual provides information on managing and monitoring your system. The Programmer's Guide provides information on the tools for programming on the Tru64 UNIX operating system. It also provides information on how to optimize the code used to create an application program, and how to optimize the results of the build process. The Asynchronous Transfer Mode manual contains information about tuning Asynchronous Transfer Mode (ATM).

The following Tru64 UNIX manuals also provide useful, relevant information:

• Technical Overview

• Network Administration

• Logical Storage Manager

• AdvFS Administration

• Systems & Options Catalog

Icons on Tru64 UNIX Printed Books

The printed version of the Tru64 UNIX documentation uses letter icons on the spines of the books to help specific audiences quickly find the books that meet their needs. (You can order the printed documentation from Compaq.) The following list describes this convention:

Some books in the documentation help meet the needs of several audiences. For example, the information in some system books is also used by programmers. Keep this in mind when searching for information on specific topics.

The Documentation Overview provides information on all of the books in the Tru64 UNIX documentation set.

Reader's Comments

Compaq welcomes any comments and suggestions you have on this and other Tru64 UNIX manuals.

You can send your comments in the following ways:

• Fax: 603-884-0120 Attn: UBPG Publications, ZKO3-3/Y32

• Internet electronic mail: readers_comment@zk3.dec.com

  A Reader's Comment form is located on your system in the following location:

  /usr/doc/readers_comment.txt
  

• Mail:

  Compaq Computer Corporation
  UBPG Publications Manager
  ZKO3-3/Y32
  110 Spit Brook Road
  Nashua, NH 03062-2698
  

  A Reader's Comment form is located in the back of each printed manual. The form is postage paid if you mail it in the United States.

Please include the following information along with your comments:

• The full title of the book and the order number. (The order number is printed on the title page of this book and on its back cover.)

• The section numbers and page numbers of the information on which you are commenting.

• The version of Tru64 UNIX that you are using.

• If known, the type of processor that is running the Tru64 UNIX software.

The Tru64 UNIX Publications group cannot respond to system problems or technical support inquiries. Please address technical questions to your local system vendor or to the appropriate Compaq technical support office. Information provided with the software media explains how to send problem reports to Compaq.

Conventions

The following conventions are used in this manual:

#

A number sign represents the superuser prompt.

% cat

Boldface type in interactive examples indicates typed user input.

file

Italic (slanted) type indicates variable values, placeholders, and function argument names.

[ | ]
{ | }

In syntax definitions, brackets indicate items that are optional and braces indicate items that are required. Vertical bars separating items inside brackets or braces indicate that you choose one item from among those listed.

colored text

In syntax definitions, literal elements are colored green. Variable values, placeholders, and function argument names are colored red. No special colored text is used outside of syntax descriptions.

.
.
.

A vertical ellipsis indicates that a portion of an example that would normally be present is not shown.

cat(1)

A cross-reference to a reference page includes the appropriate section number in parentheses. For example, cat(1) indicates that you can find information on the cat command in Section 1 of the reference pages.