Dan - the credentials we're looking for are an OS user that has sufficient permissions to access the ESX API. "root" is the example given in the credentials dialog, but we understand many of our customers will want to use a more restricted account.
See below for an excerpt out of our NPM 10 draft manual. Please let us know whether this resolves your question. Thanks!
Creating ESX Server Credentials for Orion NPM
Orion NPM uses the VMware API to poll most performance data from devices running ESX Server versions 3.5 and 4.0. Before Orion NPM can start polling ESX Servers, you must ensure that you have created credentials on your ESX Servers for the Orion NPM polling engine, as shown in the following procedure.
Note: You may assign a read-only credential to the Orion NPM polling engine.
To create ESX Server credentials for Orion NPM:
1. Log in to your ESX Server using an account with administrative privileges.
Note: Typically, the root user name and password is sufficient.
2. If you are prompted with an untrusted SSL certificate warning, click Ignore to continue using the current SSL certificate.
3. Open the Users & Groups tab, and then click Users.
4. Right-click the Users view, and then click Add.
5. On the Add New user window, complete the following procedure:
Note: The User Name and Password provided in this step must be provided either in your initial network discovery or whenever you use Web Node Management to add the current ESX Server to Orion NPM for monitoring.
a. Provide both a Login and a User Name for the Orion NPM polling engine.
b. Enter and confirm a Password.
c. Click OK.
6. Open the Permissions tab.
7. Right-click the Permissions view, and then click Add Permission.
8. On the Assign Permissions window, click Add.
9. Select the user you just created, and then click Add.
10. Click OK on the Select Users and Groups window.
11. Select an appropriate role in the Assigned Role area, and then click OK on the Assign Permissions window.
The credential you have created is now available to use for monitoring your ESX Server.
point # 11:- What is the "appropriate" Assigned Role area?
point#11 - What is the "appropriate"Assigned Role area?
I did not see a clear answer to this question when I click on the link above.