In the esxi host i received a message:
“The number of heartbeat datastores for host is 1, which is less than required: 2”
In my case i had only 1 datastore, and i did not want to see this message so in order to get rid of that i used this kb:
http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1006421
So basically, go to cluster HA settings, and click HA advanced settings button.
Add new advanced property:
das.ignoreinsufficienthbdatastore with value set to true