I am able to ping the ESX host server, and all VM's are showing as online in the console.
there are two thhings to check:
chek if thee time sync is working fine / time configured properly on esx servers with standard time servers as needed
and secondlyy you can just restart the managemnt agents to clear of anyy stale processes/ communication issues with esx and vc and inside esx:
service mgmt-vmware restart
service vmware-vpxa restart
and if you feel its storage issue u need to look into vmkervel logs to see if u find any thing there.....as well as /var/log messages
check out this similiar discussion http://communities.vmware.com/message/1672123
Please, don't forget the awarding points for "helpful" and/or "correct" answers.
Mauro Bonder - Moderator