If you follow the links, you will find 2 tools that runs on AIX servers and VIOS, and give you advise to increase you performance and correct bottlenecks:
http://www.ibm.com/developerworks/wikis/display/WikiPtype/VIOS+Advisor
VIOS advisor is included into powerVM package since version 2.2.2.1, the command is: /usr/ios/utils/part, output file is a tar into /home/padmin directory