Structure

  typedef struct { 
     nuint32   maxByteCount ; 
     nuint32   minNumOfCacheBuffers ; 
     nuint32   minCacheReportThreshold ; 
     nuint32   allocWaitingCount ; 
     nuint32   numDirtyBlocks ; 
     nuint32   cacheDirtyWaitTime ; 
     nuint32   cacheMaxConcurrentWrites ; 
     nuint32   maxDirtyTime ; 
     nuint32   numOfDirCacheBuffers ; 
     nuint32   cacheByteToBlockShiftFactor ; 
  } CACHE_INFO; 
  

Delphi Structure

  uses calwin32 
   
    CACHE_INFO = packed Record 
      maxByteCount : nuint32;  
      minNumOfCacheBuffers : nuint32;  
      minCacheReportThreshold : nuint32;  
      allocWaitingCount : nuint32;  
      numDirtyBlocks : nuint32;  
      cacheDirtyWaitTime : nuint32;  
      cacheMaxConcurrentWrites : nuint32;  
      maxDirtyTime : nuint32;  
      numOfDirCacheBuffers : nuint32;  
      cacheByteToBlockShiftFactor : nuint32 
    End; 
  

Fields

maxByteCount

Specifies the length in bytes of a cache block.

minNumOfCacheBuffers

Specifies the minimum number of cache buffers allowed on the server (default is 20, but values from 20-1000 are supported).

minCacheReportThreshold

Specifies the number of cache buffers used for the report threshold (default value is 20, but values from 0-1000 are supported).

allocWaitingCount

Specifies the number of processes waiting to allocate a cache block.

numDirtyBlocks

Specifies the number of dirty blocks waiting to be written to disk.

cacheDirtyWaitTime

Specifies the maximum wait before a Write request is written to disk (default is 3.3 seconds, but values from 0.1-10 seconds are supported).

cacheMaxConcurrentWrites

Specifies the maximum number of Write requests for changed file data that can be put in the elevator before the disk head begins a sweep across the disk (default is 50, but values from 10-100 are supported).

maxDirtyTime

Specifies the longest time (in ticks) since the server was brought up that a dirty block has waited before it was written to disk.

numOfDirCacheBuffers

Specifies the number of directory cache buffers on the server.

cacheByteToBlockShiftFactor

Specifies the n factor used in the block size equation.

Remarks

The minNumOfCacheBuffers, minCacheReportThreshold, cacheDirtyWaitTime, and cacheMaxConcurrentWrites fields can be set by using the SET console command.

When the number of cache buffers reach a number equal to the sum of the numbers specified by the minNumOfCacheBuffers and minCacheReportThreshold fields, the server sends a message warning that the cache buffers are getting low.

The block size (in bytes) is calculated using:

block size = 2 ⁿ⁺⁹

where n is the shift factor.