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<p class=MsoNormal><span lang=EN-US style='color:#1F497D'>I have also tested
RHEL5 guest on RHEL5 KVM host.<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US style='color:#1F497D'>The throughput is
about 160M/s.<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US style='color:#1F497D'>A little faster than
RHEL6, but still slow.<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US style='color:#1F497D'><o:p> </o:p></span></p>
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<p class=MsoNormal><span lang=EN-US style='color:#1F497D'> Regards<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US style='color:#1F497D'> Kirby Zhou<o:p></o:p></span></p>
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<p class=MsoNormal><span lang=EN-US style='color:#1F497D'><o:p> </o:p></span></p>
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<p class=MsoNormal align=left style='text-align:left'><b><span lang=EN-US
style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span
lang=EN-US style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>
rhelv6-beta-list-bounces@redhat.com
[mailto:rhelv6-beta-list-bounces@redhat.com] <b>On Behalf Of </b>Kirby Zhou<br>
<b>Sent:</b> Sunday, August 08, 2010 3:40 PM<br>
<b>To:</b> rhelv6-beta-list@redhat.com<br>
<b>Subject:</b> [rhelv6-beta-list] KVM performance is very poor?<o:p></o:p></span></p>
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<p class=MsoNormal align=left style='text-align:left'><span lang=EN-US><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-US>KVM performance is very poor?<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-US>I have tested a simple IO/CPU mixture testcase
under both RHEL5/Xen and RHEL6/KVM guest.<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US>The hardware configuration is DELL PE2950
with 8G CPU, E5130*2, 8G RAM, PERC 5i, 146G*3 RAID5 for virtualization pool.<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US>Each guest takes 4 VPUS and 2G RAM.<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US>It seems that KVM is very slow than Xen.<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-US>The test program spawns 10 threads, the
threads concurrently read a block device sequentially by <o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US>32k block size. It also calculates the
crc32 and md5 checksum with each read request.<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US>I use O_DIRECT to avoid the influence of
cache.<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US>Total data size is 3.2G<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-US>Under the naked machine, both RHEL5 and
RHEL6 can get 250M/s,<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US>XEN guest can get 240M/s<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US>KVM guest can get 120M/s<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-US> Regards<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US> Kirby Zhou<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p>
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