You can compare your vpxd.cfg file with the following default vpxd.cfg file for vCenter Server 5.0 GA, released on 2011-08-24:
Note: This file may have changed in later vCenter Server releases. It should only be used as a reference and not for a copying and pasting.
<config>
<level id="VmCheck">
<logLevel>info</logLevel>
<logName>VmCheck</logName>
</level>
<level id="CpuFeatures">
<logLevel>info</logLevel>
<logName>CpuFeatures</logName>
</level>
<log>
<maxFileSize>52428800</maxFileSize>
<maxFileNum>30</maxFileNum>
<level>info</level>
<memoryLevel>verbose</memoryLevel>
<compressOnRoll>true</compressOnRoll>
</log>
<alert>
<log>
<enabled>true</enabled>
</log>
</alert>
<vmacore>
<threadPool>
<TaskMax>90</TaskMax>
<threadNamePrefix>vpxd</threadNamePrefix>
</threadPool>
<ssl>
<useCompression>true</useCompression>
</ssl>
</vmacore>
<vpxd>
<filterOverheadLimitIssues>true</filterOverheadLimitIssues>
</vpxd>
<task>
<minCompletedLifetime>60</minCompletedLifetime>
</task>
</config>
VMware VirtualCenter Server サービスが起動直後に失敗し、vpxd.log ファイルが作成されない