The other day I was having a hard time with SQL. It was Sunday. It was late. I wanted to go home. But I couldnt get the SQL agent to run a backup to a remote disk. It kept failing with Access Denied.
Initially I suspected the problem was that the SQL Agent Service was running as a local account and therefore had no permissions to the remote disk. I changed the Agent to run under a domain wide account that had access to the destination folder.
Still no result. Same Error.
A little more reading, and it turns out I also need the SQL Server service to be running this account too. I changed the service logon to the domain account and it backed up to the remote disk without a hitch.
NOTE: changing logon accounts for services requires a restart of the service. In the case of the Agent, thats OK but for the SQL Server - ensure no one is busy using the database.