CACHE.EXE

Cache control program for High Performance File System (HPFS)

It is loaded on the Config.sys. The size of the cache is set on the HPFS "IFS=" statement on the Config.sys.

CONFIG.SYS
This entry controls the behavior of the HPFS cache. It is normally not set in your config.sys. Set it only if you want to change the default settings. If you encounter any problems with this statement then delete it from your config.sys file and set it up in your startup.cmd file. RUN=\OS2\Cache.exe Parameters Default settings:
 * LAZY: ON (use 1 thread)
 * BUFFERIDLE: 500 ms
 * MAXAGE: 5000 ms
 * DISKIDLE: 1000 ms
 * READAHEAD: ON

Parameters
You can use the "/" or the "-" at the beginning of each parameter.


 * /LAZY:value - Value can be ON or OFF or in the range from 0 to 64. Default = ON
 * If this parameter is not set it defaults to 3. The OS/2 online help says: "If this parameter is set no other parameters are allowed." This depends on your system, some user reported me that two lines gives errors at boot.
 * /LAZY:ON - Lazy writing is on, three threads are used.
 * /LAZY:OFF - Lazy writing is turned Off.
 * /LAZY:n - n lazy write threads are used.


 * /DISKIDLE:value - Value can be in the range from 0 to 65535. Default= 1000
 * The value is expressed in milliseconds. This is the amount of time that the disk is idle before data can be written from cache to disk.


 * /BUFFERIDLE:value - Value can be in the range from 0 to 65535. Default= 500
 * The value is expressed in milliseconds. This is the amount of time that the cache-buffer can be idle before the cache data must be written to disk. The OS/2 Online help says that the BUFFERIDLE time must be smaller than the DISKIDLE time. I think this is wrong!


 * /MAXAGE:value - Value can be in the range from 0 to 65535. Default= 5000
 * The value is expressed in milliseconds. This is the time data waits in the cache before the data is written to disk.


 * /READAHEAD:value - Value can be ON or OFF or 0 or 1. This Parameter enables the read ahead buffer. Only from Warp 4.0
 * /DIRTYMAX:value - Value can be in the range from 0 to 65535. The value is expressed in milliseconds.
 * /WRITECACHE:value - Value can be in the range from 0 to 65535. The value is expressed in kilobytes.

See the examples below.

If you want to turn lazy writing off, add this line to your config.sys: RUN=\OS2\CACHE.EXE /LAZY:OFF If you want to turn lazy writing on and set BUFFERIDLE to 4 seconds, add this line to your config.sys: RUN=\OS2\CACHE.EXE /BUFFERIDLE:4000 If you want to turn read-ahead off, add this line to your config.sys: RUN=\OS2\CACHE.EXE /READAHEAD:OFF


 * TIP:Lazy writes can also be turned ON or OFF at an OS/2 command prompt.
 * WARNING:If you include the /LAZY parameter, then the CACHE statement will IGNORE ALL OTHER PARAMETERS in the line. Therefore, if you want to turn lazy writes off (or on) and also change some other parameter, you will need two RUN statements.
 * WARNING:There is a bug in OS/2 version 2.1 which does not appear to have been fixed in Warp. You can't turn lazy writes off from the config.sys file. The WPS always turns lazy writes ON when it loads regardless of what your CACHE.EXE command sets. So, if you want lazy writes off, you will need to run the CACHE command AFTER the WPS starts. Create a CMD file to turn it off and place it in your Startup folder. The WPS has already done it's thing when the objects in the Startup folder are opened. You can also turn it off from a command prompt.

TIP: According to the OS/2 Guild running VoiceType in Warp 4.0 is speeded up with /READAHAED:ON According to one source at IBM, there are two other undocumented parameters. "Mr. HPFS" Doug Azzarito of IBM - Austin recommends them for testing only.

NOTE: Nearly everybody has his own recommendations about the correct size, so don't bother if you find different recommendations. Better try what is working best on YOUR system.

TIP: These settings can also easily done by using Warp'nGO or Xfolder Ver.080 and higher.

NOTE: The HPFS.IFS config.sys file line sets up the cache and uses the system defaults. This config.sys file line is only used to modify the cache parameters.

TIP: You can check to see what parameters the HPFS cache is currently set at by going to an OS/2 command prompt and keying in the word CACHE and pressing the enter key.

NOTE: The full line of options must be on one line. If split into more than one line, the options split off will be ignored.