LDKBMWNG parameter - Revision history

JAL: add link

2016-09-22T21:15:38Z

add link

← Older revision		Revision as of 21:15, 22 September 2016
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	<p class="code">NLRUQG * ((NSERVS + NSUBTKS) * MAXOBUF + 15)</p>		<p class="code">NLRUQG * ((NSERVS + NSUBTKS) * MAXOBUF + 15)</p>

	If the current setting of <var>NUMBUFG</var> exceeds this value and is a multiple of <var>NLRUQG</var>, no further adjustments to <var>NUMBUFG</var> are made.		If the current setting of <var>NUMBUFG</var> exceeds this value and is a multiple of <var>[[NLRUQG parameter\|NLRUQG]]</var>, no further adjustments to <var>NUMBUFG</var> are made.

	Following that, if a value for <var>LDKBMWNG</var> is specified in CCAIN and is greater than <code>0.5*NUMBUFG</code>, the value can still be adjusted:		Following that, if a value for <var>LDKBMWNG</var> is specified in CCAIN and is greater than <code>0.5*NUMBUFG</code>, the value can still be adjusted:
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	==Description==		==Description==
	<p>		<p>
	<var>LDKBMWNG</var> specifies an anticipatory write window that starts writes for any modified above-the-bar buffers that enter the window.</p>		<var>LDKBMWNG</var> specifies an anticipatory write window that starts writes for any modified ATB (above the bar) buffers that enter the window.</p>
	<p>		<p>
	When an anticipatory write for a modified buffer completes, the buffer is immediately reusable. </p>		When an anticipatory write for a modified buffer completes, the buffer is immediately reusable. </p>

JAL: /* See also */ minor formatting

2016-08-25T23:42:12Z

JAL: add links

2016-08-25T17:52:13Z

add links

← Older revision		Revision as of 17:52, 25 August 2016
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	<dl>		<dl>
	<dt>Default value		<dt>Default value
	<dd>~~(version 7~~.4) The value of <var>[[LDKBMWND_parameter\|LDKBMWND]]</var> ~~parameter~~, if set; otherwise, a value of 3.		<dd>V7.4: The value of <var>[[LDKBMWND_parameter\|LDKBMWND]]</var>, if set; otherwise, a value of 3
	<p>~~(version 7~~.5 and higher) A minimum of <code>0.5*NUMBUFG</code>.</p>		<p>V7.5 and higher: A minimum of <code>0.5*NUMBUFG</code></p>

	Before the value of <var>LDKBMWNG</var> is adjusted or recalculated, the minimum size of <var>[[~~NUMBUFG_parameter~~\|NUMBUFG]]</var> must first be determined by this formula:		Before the value of <var>LDKBMWNG</var> is adjusted or recalculated, the minimum size of <var>[[NUMBUFG parameter\|NUMBUFG]]</var> must first be determined by this formula:
	<p class="code">NLRUQG * ((NSERVS + NSUBTKS) * MAXOBUF + 15)</p>		<p class="code">NLRUQG * ((NSERVS + NSUBTKS) * MAXOBUF + 15)</p>

	If the current setting of <var>NUMBUFG</var> exceeds this value and ~~the value~~ is a multiple of <var>NLRUQG</var>, no further adjustments to <var>NUMBUFG</var> are made.		If the current setting of <var>NUMBUFG</var> exceeds this value and is a multiple of <var>NLRUQG</var>, no further adjustments to <var>NUMBUFG</var> are made.

	Following that, if a value for <var>LDKBMWNG</var> is specified in CCAIN and ~~that value~~ is greater than <code>0.5*NUMBUFG</code>, the value can still be adjusted:		Following that, if a value for <var>LDKBMWNG</var> is specified in CCAIN and is greater than <code>0.5*NUMBUFG</code>, the value can still be adjusted:
	<ul>		<ul>
	<li>		<li>The final value must be an even multiple of <var>NLRUQG</var></li>
	The final value must be an even multiple of <var>NLRUQG</var>
	</li>		<li>The final value must <i>not</i> be greater than <var>NUMBUFG</var> minus the total number of buffers that might possibly be open at any one time; that is: <p class="code">NUMBUFG - (((NSERVS+NSUBTKS)MAXOBUF)+14)NLRUQG </p></li>
	<li>
	The final value must not be greater than <var>NUMBUFG</var> minus the total number of buffers that might possibly be open at any one time; that is: <p class="code">NUMBUFG - (((NSERVS+NSUBTKS)MAXOBUF)+14)NLRUQG </p>
	</li>
	</ul>		</ul>
	<dt>Parameter type		<dt>Parameter type
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	==Description==		==Description==
	<p>		<p>
	An anticipatory write window that starts writes for any modified buffers that enter the window.</p>		<var>LDKBMWNG</var> specifies an anticipatory write window that starts writes for any modified above-the-bar buffers that enter the window.</p>
	<p>		<p>
	When an anticipatory write for a modified buffer completes, the buffer is immediately reusable. </p>		When an anticipatory write for a modified buffer completes, the buffer is immediately reusable. </p>
	<p>		<p>
	High values of <var>LDKBMWNG</var> 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>		High values of <var>LDKBMWNG</var> 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~~ [[Performance monitoring and tuning#Disk buffer monitor statistics and parameters\|Disk buffer monitor statistics and parameters]] and [[Defining the runtime environment (CCAIN)#Managing ATB storage with NUMBUFG\|Managing ATB storage with NUMBUFG]] ~~for more information.~~ </p>		==See also==
			<ul>
			<li>[[Performance monitoring and tuning#Disk buffer monitor statistics and parameters\|Disk buffer monitor statistics and parameters]] and [[Defining the runtime environment (CCAIN)#Managing ATB storage with NUMBUFG\|Managing ATB storage with NUMBUFG]] </li>

			<li><var>[[LDKBMWND parameter\|LDKBMWND]]</var> </li>
			</ul>

	[[Category:System parameters]]		[[Category:System parameters]]
	[[Category:Parameters]]		[[Category:Parameters]]

JAL: minor formatting

2016-05-09T16:17:28Z

minor formatting

← Older revision		Revision as of 16:17, 9 May 2016
Line 9:		Line 9:
	<p class="code">NLRUQG * ((NSERVS + NSUBTKS) * MAXOBUF + 15)</p>		<p class="code">NLRUQG * ((NSERVS + NSUBTKS) * MAXOBUF + 15)</p>

	If the current setting of NUMBUFG exceeds this value and the value is a multiple of NLRUQG, no further adjustments to NUMBUFG are made.		If the current setting of <var>NUMBUFG</var> exceeds this value and the value is a multiple of <var>NLRUQG</var>, no further adjustments to <var>NUMBUFG</var> are made.

	Following that, if a value for <var>LDKBMWNG</var> is specified in CCAIN and that value is greater than <code>0.5*NUMBUFG</code>, the value can still be adjusted:		Following that, if a value for <var>LDKBMWNG</var> is specified in CCAIN and that value is greater than <code>0.5*NUMBUFG</code>, the value can still be adjusted:

JDamon: Further clarification of the relationship between NUMBUFG and LDKBMWNG

2016-05-06T17:22:50Z

Further clarification of the relationship between NUMBUFG and LDKBMWNG

← Older revision		Revision as of 17:22, 6 May 2016
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	<dl>		<dl>
	<dt>Default value		<dt>Default value
	<dd>(version 7.4) The value of <var>[[LDKBMWND_parameter\|LDKBMWND]]</var>, if set; otherwise, a value of 3.		<dd>(version 7.4) The value of <var>[[LDKBMWND_parameter\|LDKBMWND]]</var> parameter, if set; otherwise, a value of 3.
	<p>(version 7.5 and higher) A minimum of <code>0.5*NUMBUFG</code>.</p>		<p>(version 7.5 and higher) A minimum of <code>0.5*NUMBUFG</code>.</p>

	~~The~~ minimum size of <var>[[NUMBUFG_parameter\|NUMBUFG]]</var> is determined by this formula:		Before the value of <var>LDKBMWNG</var> is adjusted or recalculated, the minimum size of <var>[[NUMBUFG_parameter\|NUMBUFG]]</var> must first be determined by this formula:
	<p class="code">NLRUQG * ((NSERVS + NSUBTKS) * MAXOBUF + 15)</p>		<p class="code">NLRUQG * ((NSERVS + NSUBTKS) * MAXOBUF + 15)</p>

	If the current setting of NUMBUFG exceeds this value and the value is a multiple of NLRUQG, no further adjustments are made.		If the current setting of NUMBUFG exceeds this value and the value is a multiple of NLRUQG, no further adjustments to NUMBUFG are made.

	Following that, if a value for <var>LDKBMWNG</var> is specified in CCAIN and that value is greater than <code>0.5*NUMBUFG</code>, the value can still be adjusted:		Following that, if a value for <var>LDKBMWNG</var> is specified in CCAIN and that value is greater than <code>0.5*NUMBUFG</code>, the value can still be adjusted:

ELowell: /* Summary */

2016-04-28T21:01:38Z

Summary

← Older revision		Revision as of 21:01, 28 April 2016
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	<dt>Default value		<dt>Default value
	<dd>(version 7.4) The value of <var>[[LDKBMWND_parameter\|LDKBMWND]]</var>, if set; otherwise, a value of 3.		<dd>(version 7.4) The value of <var>[[LDKBMWND_parameter\|LDKBMWND]]</var>, if set; otherwise, a value of 3.
	<p>(version 7.5 and higher) A minimum of <code>0.5*<var>[[NUMBUFG_parameter\|NUMBUFG]]</var></code>.</p>		<p>(version 7.5 and higher) A minimum of <code>0.5*NUMBUFG</code>.</p>
	~~<p>~~
	~~<var>~~NUMBUFG~~</var> will first be adjusted (rounded up) to be an even~~ multiple of ~~<var>[[~~NLRUQG ~~parameter\|NLRUQG]]</var>~~. Following that, if a value for <var>LDKBMWNG</var> is specified in CCAIN and that value is greater than <code>.5*NUMBUFG</code>, the value can still be adjusted:~~</p>~~		The minimum size of <var>[[NUMBUFG_parameter\|NUMBUFG]]</var> is determined by this formula:
			<p class="code">NLRUQG * ((NSERVS + NSUBTKS) * MAXOBUF + 15)</p>

			If the current setting of NUMBUFG exceeds this value and the value is a multiple of NLRUQG, no further adjustments are made.

			Following that, if a value for <var>LDKBMWNG</var> is specified in CCAIN and that value is greater than <code>0.5*NUMBUFG</code>, the value can still be adjusted:
	<ul>		<ul>
	<li>		<li>

ELowell: /* Description */

2016-04-28T19:38:09Z

Description

← Older revision		Revision as of 19:38, 28 April 2016
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	<p>		<p>
	When an anticipatory write for a modified buffer completes, the buffer is immediately reusable. </p>		When an anticipatory write for a modified buffer completes, the buffer is immediately reusable. </p>
	~~<p>~~
	If <var>[[NLRUQG_parameter\|NLRUQG]]</var> is set greater than 1, the value of <var>LDKBMWNG</var> is rounded up to a multiple of <var>NLRUQG</var>. <var>LDKBMWNG</var> has a minimum size of one (1). </p>
	<p>		<p>
	High values of <var>LDKBMWNG</var> 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>		High values of <var>LDKBMWNG</var> 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>

JAL: minor formatting

2016-04-28T18:07:34Z

minor formatting

← Older revision		Revision as of 18:07, 28 April 2016
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	<dt>Default value		<dt>Default value
	<dd>(version 7.4) The value of <var>[[LDKBMWND_parameter\|LDKBMWND]]</var>, if set; otherwise, a value of 3.		<dd>(version 7.4) The value of <var>[[LDKBMWND_parameter\|LDKBMWND]]</var>, if set; otherwise, a value of 3.
	<p>(version 7.5 and higher) A minimum of 0.5 * <var>[[NUMBUFG_parameter\|NUMBUFG]]</var>.</p>		<p>(version 7.5 and higher) A minimum of <code>0.5*<var>[[NUMBUFG_parameter\|NUMBUFG]]</var></code>.</p>
	<p>NUMBUFG will first be adjusted (rounded up) to be an even multiple of NLRUQG. Following that, if a value for LDKBMWNG is specified in CCAIN and that value is greater than .5*NUMBUFG, the value can still be adjusted:</p>		<p>
			<var>NUMBUFG</var> will first be adjusted (rounded up) to be an even multiple of <var>[[NLRUQG parameter\|NLRUQG]]</var>. Following that, if a value for <var>LDKBMWNG</var> is specified in CCAIN and that value is greater than <code>.5*NUMBUFG</code>, the value can still be adjusted:</p>
	<ul>		<ul>
	<li>		<li>
	The final value must be an even multiple of NLRUQG		The final value must be an even multiple of <var>NLRUQG</var>
	</li>		</li>
	<li>		<li>
	The final value must not be greater than NUMBUFG minus the total number of buffers that might possibly be open at any one time; that is: <~~br /~~>NUMBUFG - (((NSERVS+NSUBTKS)MAXOBUF)+14)NLRUQG		The final value must not be greater than <var>NUMBUFG</var> minus the total number of buffers that might possibly be open at any one time; that is: <p class="code">NUMBUFG - (((NSERVS+NSUBTKS)MAXOBUF)+14)NLRUQG </p>
	</li>		</li>
	</ul>		</ul>
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	When an anticipatory write for a modified buffer completes, the buffer is immediately reusable. </p>		When an anticipatory write for a modified buffer completes, the buffer is immediately reusable. </p>
	<p>		<p>
	If <var>[[NLRUQG_parameter\|NLRUQG]]</var> is set greater than 1, ~~then~~ the value of <var>LDKBMWNG</var> is rounded up to a multiple of <var>NLRUQG</var>. <var>LDKBMWNG</var> has a minimum size of one (1). </p>		If <var>[[NLRUQG_parameter\|NLRUQG]]</var> is set greater than 1, the value of <var>LDKBMWNG</var> is rounded up to a multiple of <var>NLRUQG</var>. <var>LDKBMWNG</var> has a minimum size of one (1). </p>
	<p>		<p>
	High values of <var>LDKBMWNG</var> 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>		High values of <var>LDKBMWNG</var> 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>

ELowell: /* Description */

2016-04-28T16:52:21Z

Description

← Older revision		Revision as of 16:52, 28 April 2016
Line 26:		Line 26:
	==Description==		==Description==
	<p>		<p>
	An anticipatory write window that starts writes for any modified buffers that enter the window</p>		An anticipatory write window that starts writes for any modified buffers that enter the window.</p>
	<p>		<p>
	When an anticipatory write for a modified buffer completes, the buffer is immediately reusable. </p>		When an anticipatory write for a modified buffer completes, the buffer is immediately reusable. </p>

ELowell: /* Summary */

2016-04-28T16:50:50Z

Summary

← Older revision		Revision as of 16:50, 28 April 2016
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	<dl>		<dl>
	<dt>Default value		<dt>Default value
	<dd>~~At V7~~.4~~, either 3, or the~~ value of <var>[[LDKBMWND_parameter\|LDKBMWND]]</var>, if set. ~~From V7~~.5 ~~onwards the default value is set to a~~ minimum of 0.5 * <var>[[NUMBUFG_parameter\|NUMBUFG]]</var>. NUMBUFG will first be adjusted (rounded up) to be an even multiple of NLRUQG. Following that, if a value for LDKBMWNG is specified in CCAIN and that value is greater than .5*NUMBUFG, the value ~~may~~ still be adjusted:		<dd>(version 7.4) The value of <var>[[LDKBMWND_parameter\|LDKBMWND]]</var>, if set; otherwise, a value of 3.
			<p>(version 7.5 and higher) A minimum of 0.5 * <var>[[NUMBUFG_parameter\|NUMBUFG]]</var>.</p>
			<p>NUMBUFG will first be adjusted (rounded up) to be an even multiple of NLRUQG. Following that, if a value for LDKBMWNG is specified in CCAIN and that value is greater than .5*NUMBUFG, the value can still be adjusted:</p>
			<ul>
	<li>		<li>
	The final value must be an even multiple of NLRUQG		The final value must be an even multiple of NLRUQG
	</li>		</li>
	<li>		<li>
	The final value must not be greater than NUMBUFG minus the total number of buffers that might possibly be open at any one time: ~~i.e~~ NUMBUFG - (((NSERVS+NSUBTKS)MAXOBUF)+14)NLRUQG		The final value must not be greater than NUMBUFG minus the total number of buffers that might possibly be open at any one time; that is: <br />NUMBUFG - (((NSERVS+NSUBTKS)MAXOBUF)+14)NLRUQG
	</li>		</li>
			</ul>
	<dt>Parameter type		<dt>Parameter type
	<dd>System		<dd>System

← Older revision		Revision as of 23:42, 25 August 2016
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	==See also==		==See also==
	<ul>		<ul>
	<li>[[Performance monitoring and tuning#Disk buffer monitor statistics and parameters\|Disk buffer monitor statistics and parameters]] ~~and~~ [[Defining the runtime environment (CCAIN)#Managing ATB storage with NUMBUFG\|Managing ATB storage with NUMBUFG]] </li>		<li>[[Performance monitoring and tuning#Disk buffer monitor statistics and parameters\|Disk buffer monitor statistics and parameters]] </li>

			<li>[[Defining the runtime environment (CCAIN)#Managing ATB storage with NUMBUFG\|Managing ATB storage with NUMBUFG]] </li>

	<li><var>[[LDKBMWND parameter\|LDKBMWND]]</var> </li>		<li><var>[[LDKBMWND parameter\|LDKBMWND]]</var> </li>