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 Version 4.0F, 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 this manual for Tru64 UNIX Version 4.0F include the following:

• Kernel subsystem attributes are now documented in the reference pages. See sys_attrs(5) for more information.

• Section 1.1 describes a methodology that you can use to configure and tune high-performance and high-availability systems.

• NetRAIN (redundant array of independent network adapters) provides high network availability by allowing you to configure multiple interfaces on the same LAN segment into a single interface. See Section 2.6.3.

• This manual includes a description of how to increase the maximum number of open file descriptors for a specific process. See Section 5.5.2.

• The mount command allows you to disable flushing file system read access times to disk. You can improve file system performance for proxy servers by specifying at mount time that the file system update only the in-memory file access time when a read system call is made to a file. The file system will update the on-disk stat structure only if the file is modified. See Section 9.2.8 for information.

• Prestoserve supports the presto-buffer-hash-size attribute, which allows you to control the size of the Prestoserve buffer cache hash table. See Section 9.2.10.

• If your system opens and then reuses many files (for example, if you have a proxy server), you may be able to improve Advanced File System (AdvFS) performance by increasing the number of AdvFS access structures that the system places on the access structure free list at startup time. See Section 9.3.4.3.

• You can prevent partial AdvFS writes if a system crash occurs. Use the chfile -L on command to enable atomic write data logging for a specified file. See Section 9.3.4.11.

• Smooth sync functionality improves UNIX File System (UFS) asynchronous I/O performance by preventing I/O spikes caused by the update daemon and increasing the chance of a buffer cache hit. Smooth sync is controlled by the vfs subsystem attribute smoothsync_age. See Section 9.4.3.7 for more information.

• You may be able to improve network performance by using the following new inet subsystem attributes:

  • The tcbhashnum attribute specifies the number of TCP hash tables. See Section 10.2.2.

  • The ipport_userreserved_min attribute specifies the minimum port number of the range from which the kernel selects outgoing ports. See Section 10.2.5.

  • The ipqs attribute specifies the number of IP input queues. See Section 10.2.19.

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

The printed version of the Tru64 UNIX documentation set is color coded to help specific audiences quickly find the books that meet their needs. (You can order the printed documentation from Compaq.) This color coding is reinforced with the use of an icon on the spines of books. The following list describes this convention:

Some books in the documentation set 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 03062-9987
  

  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.