Hi,
Here are the following steps to turn on Performance Monitoring (PM) in DCNM.
1. Log in to the Web UI and navigate to [Admin > Data Sources].
2. Add switches by providing IP address and SNMPv3/SSH credentials.
3. Assign licenses to the desired switches on the [Admin > Licenses] page.

4. Enable PM collections on the [Admin > Collections]. Select the desired device and click apply.

5. Wait approximately 30 minutes to an hour for the performance data to appear.
Thanks,
Eric