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<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>The intent of the specification was for the SM to provide such
suggestions, hence fabric policies and config could be easily controlled and
path selection can be coordinated with routing and topology knowledge (which
the SM has).<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Generally Path Record queries should be made using SGID and
DGID. In which case the SM can return multiple matching paths. It
is up to the SM to return an appropriate subset of paths. The SM can also
return multiple paths in “preferred order of use” (eg. Primary,
then secondary path for failover, etc).<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>The NumbPath parameter in the PathRecord query can specify the
maximum number of such paths of interest. Typical use cases are:<o:p></o:p></span></p>
<p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo1'><![if !supportLists]><span
style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><span
style='mso-list:Ignore'>-<span style='font:7.0pt "Times New Roman"'>
</span></span></span><![endif]><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Ask for 1 path (most applications)<o:p></o:p></span></p>
<p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo1'><![if !supportLists]><span
style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><span
style='mso-list:Ignore'>-<span style='font:7.0pt "Times New Roman"'>
</span></span></span><![endif]><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Ask for 2 paths and perform a failover algorithm or use APM (I’m
aware of quite a few applications which use failover)<o:p></o:p></span></p>
<p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo1'><![if !supportLists]><span
style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><span
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</span></span></span><![endif]><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Ask for many or all paths and perform a load balancing algorithm
across them (I’m aware of a couple applications which do this)<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:#1F497D'>Todd Rimmer<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New";
color:#1F497D'>Chief Architect </span><span style='color:#1F497D'><o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New";
color:#1F497D'>QLogic Network Systems Group</span><span style='color:#1F497D'><o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New";
color:#1F497D'>Voice: 610-233-4852 Fax: 610-233-4777<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:#1F497D'><a href="mailto:Todd.Rimmer@QLogic.com"><span style='font-family:
"Courier New";color:blue'>Todd.Rimmer@QLogic.com</span></a></span><span
style='font-size:10.0pt;font-family:"Courier New";color:#1F497D'> <a
href="http://www.QLogic.com"><span style='color:blue'>www.QLogic.com</span></a></span><span
style='color:#1F497D'><o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
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<p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span
style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>
general-bounces@lists.openfabrics.org
[mailto:general-bounces@lists.openfabrics.org] <b>On Behalf Of </b>Jordan<br>
<b>Sent:</b> Tuesday, July 14, 2009 7:26 AM<br>
<b>To:</b> general@lists.openfabrics.org<br>
<b>Subject:</b> [ofa-general] Some problem about the LID selection.<o:p></o:p></span></p>
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<p class=MsoNormal><o:p> </o:p></p>
<div>
<p class=MsoNormal>When LMC > 0 , there are 2^LMC LIDs assigned to a
port. When choosing different LID, there maybe different paths to get to
this port.<o:p></o:p></p>
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<div>
<p class=MsoNormal>In other words, different LIDs represent different paths.
But which path should I choose to get to the destination? It seems
that OpenSM<o:p></o:p></p>
</div>
<div>
<p class=MsoNormal>does not provide such algorithm .<o:p></o:p></p>
</div>
<div>
<p class=MsoNormal> <o:p></o:p></p>
</div>
<div>
<p class=MsoNormal>Does OFED provide such algorithm to manage which
path should to choose ? <o:p></o:p></p>
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