Nodata in the [DiskRead and Write]&[Network Received and Transmitted] of the reports

Hello everyone!

I'm a newbie.

The problem is the column of [DiskRead and Write]&[Network Received and Transmitted] has nodata.The others are OK(CPU,Memory etc.).  I already set the base rate for [DiskRead and Write]&[Network Received and Transmitted]  and I do some operations like copy files from one to another VM in the VM. But it still 0.00 in the report .

Can anybody tell me why? Is anything wrong in my vCenter Database?

Thank you very much!