While this error could be caused by various reasons, the following is one of the causes and resolution to the problem.
After installing VMware vCenter Update Manager 4.1 as per the deployment guide, you proceed to enable the plug-in within VI Client’s Plug-in Manager. However, once you right click on the plug-in and choose enable, you receive the following error message:
There was an error connecting to VMware vCenter Update Manager - [vCenterNameOrIP.domain.com:443].
Database temporarily unavailable or has network problems.
This can be caused if you meet the following 3 criteria:
1. You are not using a local SQL Express database for Update Manager.
2. You’ve configured your 32-bit ODBC DSN with Integrated Windows Authentication during the Microsoft SQL Server DSN Configuration window where you are asked How should SQL Server verify the authenticity of the login ID.
3. You have just finished installing VMware vCenter Update Manager and have not modified the log on properties of the VMware vCenter Update Manager Service in the services console.
The reason why this error is thrown when you enable the plug-in is because VMware vCenter Update Manager is by default installed and ran under the Local System account and therefore when you try to enable the plug-in and Update Manager makes an attempt to connect to the remote database with the 32-bit ODBC DSN with Integrated Authentication, the remote SQL database will reject the connection because Local System does not have permissions to the database. This wouldn’t be a problem if you were using a local SQL Express database because Local System has full permissions to a local SQL Express database.
To rectify this, all you need to do is change the Log on as properties of the service to the proper service account you want to use to access the database. Since Integrated Windows Authentication is going to be used, this account will be a domain account.
Once you’ve completed the change, make sure you restart the service so it will be ran as the service account.
Once you’ve made the changes and restarted the service, you should now be able to enable the plug-in within the Plug-in Manager.