LDKBMWNG parameter

# of pages in DKBM-ATB anticipatory write window

Summary

Default value

At V7.4, either 3, or the value of LDKBMWND, if set. From V7.5 onwards the default value is set to 0.5 * NUMBUFG.

Parameter type

System

Where set

On User 0's parameter line by system manager

Related products

All

Introduced

Model 204 V7.4

Description

An anticipatory write window that starts writes for any modified buffers that enter the window

When an anticipatory write for a modified buffer completes, the buffer is immediately reusable.

If NLRUQG is set greater than 1, then the value of LDKBMWNG is rounded up to a multiple of NLRUQG. LDKBMWNG has a minimum size of one (1).

High values of LDKBMWNG might unnecessarily increase the number of writes done (measured by the DKWR statistic). Low values might cause excessive waiting for buffers (measured by the DKSWAIT statistic).

Refer to the Model 204 System Manager's Guide for more information about disk buffer monitor parameters and statistics.