MS DOS Command: FASTOPEN.EXE

Reference from Microsoft MS-DOS cmd help

Description

Starts the Fastopen program, which improves performance on computers with large directories. Fastopen decreases the amount of time that MS-DOS takes to open frequently used files. Do not use this command when Windows is running.

Fastopen tracks the location of files on a hard disk and stores the information in memory for fast access.

Syntax

FASTOPEN drive:[[=]n] [drive:[[n][...]] [/X]

In your CONFIG.SYS file, use the following syntax:

INSTALL=[[dos-drive:]dos-path]FASTOPEN.EXE drive:[[=]n] [drive:[[=]n][...]] [/X]

Warning: To avoid losing data, do not run a defragmentation program such as Microsoft Defragmenter while FASTOPEN.EXE is loaded.

Parameters

[dos-drive:]dos-path	Specifies the location of FASTOPEN.EXE.
drive:	Specifies a hard disk drive for which you want Fastopen to track the opening of files.
n	Specifies the number of files Fastopen can work with at the same time. Valid values for n are in the range 10 through 999. The default value is 48.

Switch

/X

Creates the name cache in expanded memory instead of in conventional memory. The name cache is an area of memory in which MS-DOS stores (caches) the locations and names of the files that you open. This cache conforms to version 4.0 of the Lotus/Intel/Microsoft Expanded Memory Specification (LIM EMS).

Remarks

How Fastopen tracks information

Every time you open a file, Fastopen records its name and location in the name cache. If you later reopen a file recorded by Fastopen, the access time is greatly reduced.

Limits on using Fastopen

Fastopen works only on hard disks and does not work over a network. You can use Fastopen with as many as 24 hard-disk partitions at one time. For each partition, Fastopen can track the number of files specified by the n parameter. The maximum number of files that Fastopen can track on all partitions is 999.

You cannot run more than one copy of Fastopen at the same time. If you want to change the Fastopen settings, you must restart MS-DOS.

You should not use the Fastopen command from MS-DOS Shell, because doing so can lock up your machine.

Memory requirements for Fastopen

Fastopen requires approximately 48 bytes of memory for each file that it tracks.

Adding the FASTOPEN command to your CONFIG.SYS file

You can add a Fastopen command to your CONFIG.SYS file by using the INSTALL command. Use this technique when you do not want to start Fastopen from the MS-DOS command line or from your AUTOEXEC.BAT file.

Examples

If you want MS-DOS to track the location of as many as 100 files on drive C, add the following line to your CONFIG.SYS file:

install=c:\dos\fastopen.exe c:=100