<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<meta http-equiv=Content-Type content="text/html; charset=us-ascii">
<meta name=Generator content="Microsoft Word 11 (filtered medium)">
<style>
<!--
/* Font Definitions */
@font-face
{font-family:Tahoma;
panose-1:2 11 6 4 3 5 4 4 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman";}
a:link, span.MsoHyperlink
{color:#0000A0;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{color:purple;
text-decoration:underline;}
span.EmailStyle17
{mso-style-type:personal-compose;
color:black;}
@page Section1
{size:8.5in 11.0in;
margin:1.0in 1.25in 1.0in 1.25in;}
div.Section1
{page:Section1;}
-->
</style>
<!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
</head>
<body lang=EN-US link="#0000A0" vlink=purple>
<div class=Section1>
<p class=MsoNormal><font size=3 color=black face="Times New Roman"><span
style='font-size:12.0pt;color:black'>We have been troubleshooting a major
performance issue with out Lustre systems when switching from 1.6.4.3 to 1.6.5.
<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 color=black face="Times New Roman"><span
style='font-size:12.0pt;color:black'>Using a patchless client and running a
single thread, single file (50GB) dd copy, the 1.6.4.3 client wrote up to
1.3GB/s. Using the same system and changing only the client to 1.6.5, write
speed went down to 700MB/s.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 color=black face="Times New Roman"><span
style='font-size:12.0pt;color:black'>We found one configuration option
different by default between the two clients. In 1.6.4.3, checksum is disabled
by default. In 1.6.5, checksum is enabled by default. Disabling checksum on the
1.6.5 client resulted in a performance increase to 1.1GB/s.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 color=black face="Times New Roman"><span
style='font-size:12.0pt;color:black'>Question – are there other option
changes between 1.6.4.3 and 1.6.5 that might account for the remaining 200MB/s
loss in performance?<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 color=black face="Times New Roman"><span
style='font-size:12.0pt;color:black'><o:p> </o:p></span></font></p>
<div>
<div>
<p class=MsoNormal><strong><b><font size=1 color=navy face=Tahoma><span
style='font-size:7.5pt;font-family:Tahoma;color:navy'>Bob Hayes</span></font></b></strong><strong><b><font
size=2 color=navy face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma;
color:navy'> </span></font></b></strong><font color=black><span
style='color:black'><o:p></o:p></span></font></p>
<p class=MsoNormal><font size=1 color=navy face=Tahoma><span style='font-size:
7.5pt;font-family:Tahoma;color:navy'>System Administrator</span></font><font
color=navy><span style='color:navy'><br>
Intel-</span></font><font size=1 color=navy face=Tahoma><span style='font-size:
7.5pt;font-family:Tahoma;color:navy'>SSG-DRD-DP</span></font><font color=navy><span
style='color:navy'><br>
</span></font><font size=1 color=navy face=Tahoma><span style='font-size:7.5pt;
font-family:Tahoma;color:navy'>Office: 253-371-3040</span></font><font
size=1 color=black><span style='font-size:7.5pt;color:black'><o:p></o:p></span></font></p>
<p class=MsoNormal><font size=1 color=navy face=Tahoma><span style='font-size:
7.5pt;font-family:Tahoma;color:navy'>Cell: 253-441-5482</span></font><font
color=navy><span style='color:navy'><br>
</span></font><font size=1 color=navy face=Tahoma><span lang=DE
style='font-size:7.5pt;font-family:Tahoma;color:navy'>e-mail: </span></font><font
color=black><span style='color:black'><a href="mailto:robert.n.hayes@Intel.Com"><font
size=1 face=Tahoma><span lang=DE style='font-size:7.5pt;font-family:Tahoma'>robert.n.hayes@Intel.Com</span></font></a></span></font><font
color=navy><span style='color:navy'><o:p></o:p></span></font></p>
</div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
</div>
</body>
</html>