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This sets up the disk cache for FAT formatted hard drives but not for floppy drives.

DISKCACHE=Size,LW,Threshold,AC:Drives

Parameters:

• Size

  Size can be in the range from 48 to 14400 or D .
  If set to D the cache size is 5% of RAM up to a limit of 4 Mbytes.
  Default = D
  The size is expressed in Kbytes.

• LW

  If this parameter is set, the lazy writing of data to disk is enabled. With lazy writing all disk writes are temporarily held in memory until the system is not busy. Lazy writing increases performance, but be careful as an unexpected power off may cause data loss.

• Threshold

  Specifies the threshold size. All files which are bigger than the threshold size are NOT cached. Set it to 32 which is reported as an optimum value.
  Threshold can be in the range from 4 to 128
  This value is expressed in sectors with a size of 512 Byte. The default is 4 sectors, i.e, all files greater than 2048 Bytes (4 asterisk 512) are not cached.

• AC:drives

  The AC parameter specifies which drives should be checked by chkdsk.exe during start up after an improper shut down. Add only the drive letter without the colon. If you want to run chkdsk.exe on a drive at every start up add a plus sign (+) in front of the drive letter.

See the examples below.

To use 1 megabyte of space as your disk cache size for FAT drives, enable lazy writing, disable the autocheck feature and use the default of 2048 bytes for the threshold size, use this line:

The following line sets the DISKCACHE to 512 Kbytes, a threshold size of 16 Kbytes, turns lazy writing on, autochecks drive C: after improper shut down and autochecks drive F: at every start up:

This DISKCACHE command use 10% of RAM for the cache, disables lazy writing, uses 4 Kbytes as the threshold size and enables autocheck on every startup for drives C: and E:.

Platform Support:

OS/2 2.x	OS/2 3.0	OS/2 4.0
Yes	Yes	Yes