Commvault Security > Domain and organization > deleting an existing Name Server entry

While trying to delete a domain entry (name server entry) under domain and organization in security, commvault shows a confirmation dialog box 

“This operation permanently deletes all clients and their associated data for the selected Name Server. Are you sure you want to delete the selected Name Server ?” 

 what does this really imply?

The validation check kept failing with verification error stating either credentials are wrong or the provider couldn’t be contacted for verification, hence we created a new entry for the same domain and validation check is successful on that.

I want to get rid of the old entry for which the validation is failing. Is it safe to delete the old domain entry (name server)