Preface

Advanced File System (AdvFS) is the default file system for the Compaq Tru64 UNIX operating system. AdvFS is a log-based file system that provides flexibility, compatibility, data availability, and high performance. AdvFS takes advantage of the 64-bit computing environment and is designed to handle files and filesets of nearly 16 terabytes. For hardware and software requirements, see the Tru64 UNIX Software Product Description and the AdvFS Utilities Software Product Description.

AdvFS Utilities, which is licensed separately from the Tru64 UNIX operating system, provides additional file management capabilities and a graphical user interface (GUI) to simplify system administration. The AdvFS GUI, which runs under the Common Desktop Environment (CDE), features menus, graphical displays, and comprehensive online help that make it easy to perform AdvFS operations. In addition, the GUI displays summarized system status information. It includes utilities to add volumes, create clones, stripe files, and balance domains.

This guide describes AdvFS and AdvFS Utilities in detail. It provides information on features and functions, and it gives suggestions on how to use these functions. Many functions can be accomplished through either the command line, the GUI, or the SysMan Menu (see sysman(8)).

Introducing AdvFS

The configuration of AdvFS differs from the traditional UNIX file system. In AdvFS, the physical storage layer is managed independently of the directory layer. System administrators can add and remove storage without unmounting the file system or halting the operating system. As a result, configuration planning is less complicated and more flexible.

From a user's perspective, AdvFS behaves like any other UNIX file system. End users can use the mkdir command to create new directories, the cd command to change directories, and the ls command to list directory contents. AdvFS logical structures, quota controls, and backup capabilities are based on traditional file system design. AdvFS replaces or eliminates several standard commands, such as newfs, dump, restore, and fsck. AdvFS commands and utilities and a comparison of AdvFS and UFS commands are detailed in Appendix B.

Without taking an AdvFS system off line, system administrators can perform backups, file system reconfiguration, and file system tuning. End users can retrieve their own unintentionally deleted files from predefined trashcan directories or from clone filesets without assistance from system administrators.

AdvFS supports multivolume file systems, which enables file-level striping (spreading data to more than one volume) to improve file transfer rates for I/O-intensive applications. Logical Storage Manager (LSM), which allows volume-level striping, can be incorporated into AdvFS configurations.

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Advanced File System Features

The following table lists the main features and benefits of AdvFS.

AdvFS Features and Benefits

Feature Benefit
Rapid crash recovery Write-ahead logging eliminates the need to use the fsck utility to recover from a system failure. The file system recovery time is rapid and is independent of file system size.
Extended capacity, scalability The design supports large-scale storage systems.
High performance An extent-based file allocation scheme consolidates data transfer.
Disk spanning* A file or file system can span multiple disks within a shared storage pool.
Unified buffer cache (UBC) This cache interacts with the virtual memory system to dynamically adjust the amount of physical memory being used to cache file data.
Online defragmentation System performance improves by defragmenting the data on the disk while the system remains in use. Defragmentation makes file data more contiguous on the storage medium.
Online resizing* The size of the file system can be dynamically changed by adding or removing disk volumes while the system remains in use. This enables both online storage configuration and online file system maintenance.
File-level striping* Distributing file data across multiple disk volumes improves file transfer rates.
Online backup* File system contents can be backed up to media without interrupting the work flow of system users by using fileset clones.

AdvFS Features and Benefits (cont.)

Feature Benefit
File undelete* Users can recover deleted files without assistance from system administrators.
Quotas AdvFS supports quotas for users and groups as well as for filesets.
Graphical user interface* The GUI simplifies file system management by organizing AdvFS functions into menu-selected tasks and by displaying file system status.

* This feature requires the optional AdvFS Utilities license.

What's New in Tru64 UNIX Version 5.1

The following features have been added to AdvFS:

Conventions

This guide uses the following conventions:

%

A percent sign represents the C shell system prompt.

$

A dollar sign represents the system prompt for the Bourne, Korn, and POSIX shells.

#

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.

. . .

In syntax definitions, a horizontal ellipsis indicates that the preceding item can be repeated one or more times.

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.

[Ctrl/x]

This symbol indicates that you hold down the first named key while pressing the key or mouse button that follows the slash. In examples, this key combination is enclosed in a box (for example, [Ctrl/C] ).

License Registration

AdvFS is the file system default on the operating system. AdvFS Utilities is a separately licensed product that provides additional processing capabilities. Before you can use the file system utilities, you must register a license product authorization key (PAK) for AdvFS Utilities. Contact your software support organization for additional information.

Related Information

Other useful documentation includes: