LDKBMWNG parameter: Difference between revisions
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<p>An anticipatory write window that starts writes for any modified buffers that enter the window</p> | <p>An anticipatory write window that starts writes for any modified buffers that enter the window</p> | ||
<p>When an anticipatory write for a modified buffer completes, the buffer is immediately reusable. </p> | <p>When an anticipatory write for a modified buffer completes, the buffer is immediately reusable. </p> | ||
<p>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). </p> | <p>If <var>[[NLRUQG_parameter|NLRUQG]]</var> 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). </p> | ||
<p>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).</p> | <p>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).</p> | ||
<p>Refer to the <var>Model 204 System Manager's Guide</var> for more information about disk buffer monitor parameters and statistics. </p> | <p>Refer to the <var>Model 204 System Manager's Guide</var> for more information about disk buffer monitor parameters and statistics. </p> | ||
[[Category:System parameters]] | [[Category:System parameters]] | ||
[[Category:Parameters]] | [[Category:Parameters]] | ||
Revision as of 10:55, 27 November 2014
# 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.