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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>We have an appliance that uses the CentOS 4.4 Plus kernel
with XFS on an EMC RAID array that performs about ¼ or less as well with cached
i/o than with direct i/o. With direct i/o we get about 32Mb/s throughput or
better, but if we enable the cache for the EMC RAID, we only get 8Mb/s or
less. This doesn’t happen if we use JFS, where we get a little less than
32Mb/s throughput with or without cache enabled, on the same hardware and
CentOS, but there are some features in XFS that we use that are not available
in JFS..<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Any thoughts on this?<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Thanks.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
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