Thanks for the information.
I have a query about the performance measuring in ESX. which file do we refer for the performance of ESX Server other than the Performance Tab?
The other key built-in mechanism for performance monitoring is ESXTOP - it's a tool in the ESX Service Console. There's also a version of it in the vSphere Management Assistant that you can run against ESX/ESXi servers remotely - RESXTOP.
Here's a site which will tell you all about it: http://www.yellow-bricks.com/esxtop/