Friday, November 14, 2014

Article Number: 9899




DISABLING WRITE CACHING





To avoid potential write caching problems, you may want to



disable the DOS 6 SmartDrive write caching feature.



However, first you will need to know about the DOS 6



AUTOEXEC.BAT file.





Below is a typical DOS 6 AUTOEXEC.BAT file for an 80286, an



80386, or an 80486 machine.





@ECHO OFF



PATH C:\DOS;C:\WINDOWS;C:\UTILS



PROMPT $P$G



SET TEMP=C:\DOS



SMARTDRV





You can use EDIT, the built-in DOS editor, to make or modify the



AUTOEXEC.BAT file or the CONFIG.SYS file. Both of these



files reside on the root directory of your start-up disk. Remember,



the changes you make when you modify an existing



AUTOEXEC.BAT or CONFIG.SYS file will not take effect until



you restart your computer. Never make a modification to either



the AUTOEXEC.BAT file or the CONFIG.SYS file without first



making a backup of these important files on diskette. If your



start-up disk is drive C, you can load the AUTOEXEC.BAT file into



EDIT by typing:





edit c:\autoexec.bat





When you are in EDIT, you can press for more help. If



you make changes, don't forget to save the file by pressing:







f



s





Note that the last line in the sample AUTOEXEC.BAT file is



SMARTDRV. SMARTDRV is a disk cache that works with



computers that have extended memory. If you have an 80286 or



greater machine with at least 1 megabyte of memory, then you can



probably use SMARTDRV. A disk cache uses a portion of memory



to store information that DOS reads from disk. DOS can read



information from the disk cache much faster than it can read



information from a drive. The result is that you will get a big



performance boost if you use a disk cache.





The DOS 6 SMARTDRV will cache both floppy and hard drives



and is faster than the DOS 5 SMARTDRV. The DOS 6



SMARTDRV is very similar to the one that is included with



WINDOWS 3.1 and can be loaded in the AUTOEXEC.BAT file.



The DOS 6 version of SMARTDRV will automatically calculate



values by determining how much upper memory exists in your



machine. It will also automatically load itself into high



memory if it is available.





The DOS 6 SMARTDRV will do read caching and write caching



for hard drives and read caching for floppies. With write



caching, you could lose data if you turn your computer off



immediately after quitting a program.





IT IS BEST TO WAIT AT LEAST FIVE SECONDS AFTER YOU QUIT AN



APPLICATION BEFORE YOU TURN THE MACHINE OFF.





On drives that are write cached, SMARTDRV waits until the



cache is about full, or until there has been about 5 seconds of



idle time, before writing the data to your hard drive. If you



want to force the write cache to immediately write the data to



the hard drive, type:





smartdrv /c





ÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜ





To avoid potential write caching problems, you may want to



disable the DOS 6 SmartDrive write caching feature.





ÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜ





You can disable write caching by following the SMARTDRV



command with the letters of your hard drives. Suppose you had



hard drives C, D, E, and you wanted to disable write caching on



these drives. Use the DOS EDIT program to change the



SMARTDRV line in the AUTOEXEC.BAT file to read the



following:





SMARTDRV C D E





The above line tells DOS to allow read caching while disabling



write caching for drives C, D, and E. Don't try to cache a



DoubleSpaced drive. SmartDrive will not cache compressed



drives (DoubleSpaced drives), CD-ROM drives, network drives,



or RAM drives. If you are running DoubleSpace, you can get



information on all your drives by typing:





dblspace /info





If you want to see which drives SMARTDRV is caching, at the



system prompt type:





smartdrv





For more information on the DOS 6 SMARTDRV command, type:





help smartdrv











This section is finished. It is an excerpt from LEARNING DOS FOR



THE COMPLETE NOVICE, by Steven Woas, copyright 1993. When you register



this program, you will receive the 336 page book, LEARNING DOS FOR THE



COMPLETE NOVICE which covers DOS 3.2 through DOS 6. To register send



$15.95 plus $2.00 for shipping to:







Celestial Press



4424 Dohrcrest Dr.



Suite C



New Port Richey, FL 34652





Phone (813) 845-8522



US customers can order toll-free 1-800-330-3311



Fax (813) 845-8522





We accept Visa & MasterCard





Florida orders add 6% sales tax.


No comments:

Post a Comment