Performance Charts in VI Client

Hi There,

we are using ESX Server 3.0.2 with no VC-Server in place. When I try to configure Performance Chart Option in VI-Client I am not able to set up a from:  - to: time period nore am I able to choose say the last 3 hours (the options are greyed out in VI-Client). Why I am not able to do this? Is this a VC-Server only feature? 

I like to get a performance chart of the last 24 hours. How do I manage it?

Thanks for your help!

Best....Andreas