no performance data of esxi 5.x in the summary or the performance tab

symptoms:

• cpu, memory usage is 0 in the summary tab in the vCenter and vWC (vsphere web client)
• performance chart is blank for realtime or past history in the vCenter and vWC (vsphere web client).
• vsphere client displays the cpu, memory usage and the performance data of the host.

Resolution: restart the host agents by ./sbin/service.sh restart, disconnect and connect the host from the vcenter by right clicking the host.
If the above doesnt work then try these below
http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1032908
http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=5296658
http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1003878