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Text File | 1992-03-18 | 14.7 KB | 355 lines

SMARTDRV.DOC File (C) Copyright Microsoft Corporation, 1992 ================================< Contents >================================= This file has 2 parts: Part Contents ---- -------- 1 Using the SMARTDRV.EXE Disk-Caching Program 2 Additional Notes =============< Part 1: Using the SMARTDRV.EXE Disk-Caching Program >========= Microsoft Macro Assembler includes SMARTDRV.EXE version 4.0, a sophisticated block-oriented disk-caching program that significantly improves assembly and link times. SMARTDRV.EXE is not required by MASM, but it can reduce the amount of time your computer spends reading data from your hard disk. SMARTDRV.EXE replaces the older version, SMARTDRV.SYS, and is compatible with all versions of Windows 3.x. SMARTDRV.EXE sets aside some expanded or extended memory as a cache for its own use. SMARTDRV.EXE uses this disk cache to store the information read from the hard disk when an application needs information from your hard disk. When an application attempts to read additional information from the hard disk, the SMARTDRV.EXE program supplies the information directly from its cache instead. If you are using RAMDRIVE.SYS to create one or more RAM drives, and are limiting the memory assigned to SMARTDRV.EXE as a result, you can increase system speed by reassigning some or all of the memory away from the RAM drive and adding it to the memory available to SMARTDRV.EXE. SMARTDRV.EXE automatically loads itself into HMA under MS-DOS 5.0 if EMM386.EXE is loaded and upper-memory blocks are available as a result of a DOS=UMB or DOS=UMB,HIGH command in your CONFIG.SYS file. SMARTDRV.EXE can also be loaded into HMA with third-party memory managers such as 386-Max. SMARTDRV.EXE must be specified in both your AUTOEXEC.BAT file and CONFIG.SYS file because there are actually two device drivers in a single file: a double-buffer driver and a disk cache. The double-buffer driver is installed in CONFIG.SYS, and the cache component of SMARTDRV.EXE is installed in AUTOEXEC.BAT. Some disk controllers do not need double buffering; using this option when you do not need it results in a small performance penalty. Therefore, once your system is running with SMARTDRV.EXE, type: SMARTDRV at the command-line prompt. SMARTDRV.EXE displays disk-cache status information about your system that looks like this: Microsoft SMARTDrive Disk Cache version 4.0 Copyright 1991,1992 Microsoft Corp. Cache size: 1,048,576 bytes Cache size while running Windows: 1,048,576 bytes Disk Caching Status drive read cache write cache buffering -------------------------------------------- A: yes no no B: yes no no C: yes yes yes D: yes yes - For help, type "Smartdrv /?". Note ---- If every line in the Buffering column is No, then you can safely remove the DEVICE statement for SMARTDRV.EXE from your CONFIG.SYS file. SMARTDRV.EXE always copies data to your hard disk when you turn off your computer. It also writes all data to the disk when an application calls the MS-DOS reset disk function. If you want to force data to be written to disk, use the /C command-line option. If you use a third-party program to reboot your machine from a batch file, you should make sure you have SMARTDRV /C in the batch file prior to the reboot command. Failure to do so may cause data loss. You can use command-line options to control the size of the cache element (/E) and the size of the read-ahead buffer (/B). The read-ahead buffer is additional information that SMARTDRV.EXE reads when the application reads information from the hard disk. The size must be specified in bytes, and the element size must be one of the following: 1024, 2048, 4096, or 8192. The read-ahead buffer must be a multiple of the element size, cannot be less than the element size, and cannot exceed 32768. The defaults are 8192 for the element size and 16384 for the read-ahead buffer. Because these will occupy conventional or UMB memory space, making them larger reduces the memory MS-DOS applications have available. You can start the SMARTDRV.EXE program by typing SMARTDRV at the MS-DOS prompt before you start Windows, or by placing a command line in your AUTOEXEC.BAT file. The syntax is: [[drive:]] [[path]]SMARTDRV.EXE[[ [[drive[[+|-]] ]]...]] [[/E:ElementSize]] [[InitCacheSize]] [[WinCacheSize]] ]] [[/B:BufferSize]] [[/C]] [[/R]] [[/L]] [[ /Q]] [[/S]] [[/?]] The following list describes the command-line options available for SMARTDRV.EXE: drive ----- Specify the letter of the disk drive for which you want to control caching. If you don't specify a drive letter, floppy disk drives are read-cached but not write-cached, hard disk drives are read- and write-cashed, and CD-ROM and network drives are ignored. You can specify multiple disk drives. path ---- Specify the location of the SMARTDRV.EXE file. + | - ----- Enable (+) or disable (-) caching. Use the plus (+) and minus (-) signs to override the default settings. If you specify a drive let- ter without a plus or minus sign, read-caching is enabled and write-caching is disabled. If you specify a drive letter followed by a plus sign (+), read- and write-caching are enabled. If you specify a drive letter followed by a minus sign(-), read- and write-caching are disabled. /E:ElementSize -------------- Specify in bytes the amount of the cache SMARTDRV.EXE moves at a time. This must be greater than or equal to 1, and a power of 2. The default value is 8K. InitCacheSize ------------- Specify the size in kilobytes of the cache when SMARTDRV.EXE starts (before Windows is running). The size of the disk cache affects SMARTDRV.EXE's efficiency. In general, the larger the cache, the less often SMARTDRV.EXE needs to read information from the disk, which speeds up your system's performance. If you do not specify an InitCacheSize value, SMARTDRV.EXE sets the value according to how much memory your system has (see the list following this list). WinCacheSize ------------ Limit the amount (in kilobytes) Windows can reduce the cache size. Windows reduces the size of the cache to recover memory for its own use. Windows and SMARTDRV.EXE then cooper- ate to provide optimum use of your system memory. When you quit Windows, Windows restores the cache to its normal size. The default value depends on how much available memory your system has (see the list following this list). If you specify a value for InitCacheSize that is smaller than the value specified for WinCacheSize, InitCacheSize is set to the same size as WinCacheSize. /B:BufferSize ------------- Specify the size of the read-ahead buffer. The next time the application is to read information from that file, it can read it from memory instead. The default size of the read-ahead buffer is 16K. Its value can be any multiple of ElementSize. /C -- Write all cached information from memory to the hard disk. SMARTDRV.EXE writes information from memory to the hard disk at times when other disk activity has slowed. You might use this option if you are going to turn off your computer, and you want to make sure all cached information has been written to the hard disk. /R -- Clear the contents of the existing cache and restart SMARTDRV.EXE. /L -- Prevent SMARTDRV.EXE from loading into upper-memory blocks (UMBs), even if there are UMBs available. You can use this option of you are using MS-DOS version 5.0 or later and UMBs are enabled. /Q -- Prevent the display of SMARTDRV.EXE information on your screen. /S -- Display additional information about the status of SMARTDRV.EXE. /? -- Display online Help about the SMARTDRV.EXE command and options. The following list shows the default values for InitCacheSize and WinCacheSize, depending on the amount of available extended memory on your computer. Extended Memory <= 1 MB <=2 MB <=4 MB <=6 MB <=6 MB InitCacheSize All 1 MB 1 MB 2 MB 2 MB WinCacheSize Zero 256K 512K 1 MB 2 MB Note ---- Do not put the SMARTDRV.EXE cache in the expanded memory provided by EMM386.EXE. EMM386.EXE uses extended memory to emulate expanded memory that other programs can use. Although SMARTDRV.EXE can use this emulated expanded memory for its cache, it may not make your program run as quickly as it would using extended memory. Because the optimal cache size for SMARTDRV.EXE depends on the programs you run, and on your system configuration, there is no single best setting. You should experiment to find the best cache size for your system after saving a copy of your CONFIG.SYS file. For more information, see your Windows User's Guide. =========================< Part 2: Additional Notes >========================= Avoiding Data Loss When Using SMARTDRV.EXE ------------------------------------------ SMARTDRV.EXE does not write data to disk immediately. If your computer should crash after the time data is written to the cache and before the data is written to the disk, data can be lost. Issuing the following command causes SMARTDRV to write all data in the cache to the disk: SMARTDRV /c Setup May Not Detect Foreign Disk Cache --------------------------------------- Setup may install SMARTDRV.EXE if it does not detect the foreign disk cache installed on your system. Remove the DEVICE statements for SMARTDRV.EXE from your AUTOEXEC.BAT and CONFIG.SYS files to resolve this problem. Programs That May Be Incompatible with SMARTDRV.EXE --------------------------------------------------- The following applications may be incompatible with SMARTDRV.EXE, version 4.0: - The Disk Protect feature in Norton Utilities version 6.0 Do not use the Disk Protect feature in Disk Monitor. If you do, you will encounter an error and your system may hang if you try to write to the protected drive. If you want to write to and cache a protected drive, use the Norton cache program when using Disk Monitor. - The Calibrate program in Norton Utilities version 6.01 Calibrate fails on the Disk Mapping test if SMARTDRV is enabled. - DoubleDisk from Vertisoft Do not enable write-behind caching for DoubleDisk compressed partitions. - Storage Dimensions SCSI Driver (SSTOR.SYS) Using the SSTOR.SYS driver, the SCSI drive appears corrupted when SMARTDRV is loaded. The disk's contents are not altered, but they are inaccessible when using SMARTDRV. The following drivers, installed in a CONFIG.SYS file, are incompatible with SMARTDRV.EXE version 4.0: - The SuperStor utility from Addstor (SSTORDRV.SYS) Do not use the Create Mountable Drive or Mount and Dismount features of SuperStor after SMARTDRV is loaded. You must configure your SuperStor partitions before loading SMARTDRV. If your AUTOEXEC.BAT file includes "mount" configuration commands, make sure that the SMARTDRV command line follows the SuperStor configuration command lines. Also, you will receive read-write errors if you use SMARTDRV to cache a SuperStor compressed drive. To prevent SMARTDRV from caching the compressed drive, you must include the driver letter- option on the SMARTDRV command line. For example, if drive C is the uncompressed drive, and drives E and F are the compressed SuperStor drives, you would type the following command line or include it in your AUTOEXEC.BAT file: smartdrv e- f- - The network driver from DNA Networks Inc. (STATION.SYS) Using both STATION.SYS and SMARTDRV may cause your system to hang. - Versions prior to version 7.x of the driver for the Bernoulli Box (RCD.SYS) The RCD.EXE program requires that driver RCD.SYS be installed to use the Bernoulli Box. When SMARTDRV is running, RCD.EXE does not recognize that RCD.SYS has been installed. - The Norton Antivirus utility (NAV_.SYS and NAV&.SYS) The NAV_.SYS and NAV&.SYS drivers for the Norton Antivirus utility may generate "Not enough memory" errors or hang your system when loading SMARTDRV.EXE. One workaround is to use the /L command-line option to load SMARTDRV.EXE into low memory. An alternative is using the /B option with NAV&.SYS to avoid the NAV&.SYS bug that causes your system to hang. The following driver, installed in an AUTOEXEC.BAT file, is incompatible with SMARTDRV.EXE version 4.0: - DataMonitor version 7.1 by PC Tools (DATAMON.*) Loading DataMonitor after SMARTDRV is installed may cause your system to hang. ============================================================================= Microsoft, MS, MS-DOS, and CodeView are registered trademarks, and Windows is a trademark of Microsoft Corporation. 386-Max is a trademark of Qualitas, Inc. Bernoulli Box is a trademark of Iomega Corporation. Norton Utilities is a registered trademark of Peter Norton Computing. SuperStor is a trademark and Addstor is a registered trademark of Addstor, Inc. NOTE: Microsoft improves its languages documentation at the time of reprinting, so some of the information in this file may already be included in your manuals.