If Sharepoint is installed with its own SQL instance in an all-in-one configuration and a content database is attached to a remote SQL instance the backup of that added content DB may fail with an access denied message.
Final error: 0xe0001602 - Access is denied (SharePoint backup).
Final error category: Security Errors
At the end of the backup set for the remote content DB is this message:
This backup set may not contain any data.
A debug of the Backup Exec media server will show the following in the Remote Agent debug (beremote):
 2012-09-13T14:44:59.227 [fsys\spsv2\spsv2grb - Unable to get site table!
 2012-09-13T14:44:59.230 [fsys\spsv2\spsv2grb - Initialization failed
 2012-09-13T14:44:59.230 [ndmp\loops] - BACKUP_LP_ENV::AttachToDLE
() failed to attach to (null). Reason is 0xe0008488
 2012-09-13T14:44:59.230 [ndmp\loops] - LP_ENV::MsgError: error
0xe0008488 processing object <Unknown>
When installing Sharepoint in an all-in-one configuration the SQL instance installed has the remote connection ability turned off. The ability to connect to the Sharepoint instance of SQL is required for the Backup Exec Sharepoint during the GRT metadata collection phase. This connection occurs from the server hosting the Sharepoint content database over to the Sharepoint Configuration Database hosted in the Sharepoint SQL instance. Without the ability for remote connections in the Sharepoint SQL instance this phase of the backup will fail.
Enable remote connections in the Sharepoint SQL instance as follows on the Sharepoint Server:
1.Open SQL Server Configuration Manager. Click Start | Programs | Microsoft SQL Server 2008 | Configuration Tools | SQL Server Configuration Manager.
2.In SQL Server Configuration Manager, select SQL Server Services on the left window. If the state on SQL Server Browser is not running, you must enable automatic startup and start the service. If the SQL Server Browser service is already running, skip to step 6..
3.Double-click on SQL Server Browser, the Properties window will show up. If necessary, set the account for starting the SQL Server Browser Service as Local Service account.
4.In the SQL Server Browser Properties, select the Service tab and change Start Mode to Automatic. Click OK to apply changes.
5.Back to SQL Server Configuration Manager, right-click on SQL Server Bowser on the right window and select Start to start the service.
6.On the left window, expand SQL Server Network Configuration -> Protocols for SHAREPOINT. You see that TCP/IP protocol status is disabled.
7.Right-click on TCP/IP and select Enable to enable the protocol.
8.There is a pop-up shown up that you have to restart the SQL Service to apply changes.
9.On the left window, select SQL Server Services. Select SQL Server (SHAREPOINT) on the right window -> click Restart. The SQL Server service will be restarted.