Symptoms
The error is reported duing backup of SQL SERVER using VSS-aware Backup Set or when attempting to create a SQL Server (traditional) backup set:
SQL Server does not exist or access denied. ConnectionOpen (Connect()).
(select top 1 convert(varchar(25),(isnull(differential_base_lsn, first_lsn))) as base_lsn from msdb..backupset where database_name = master order by backup_start_date desc ) (ServerName\master)
AND:
Failed to retrieve LSN information of the database. All differential backups based on this full backup are unreliable. (ServerName\master)
Cause
1. Backing up a remote instance of Microsoft SQL Server or SQL Server Express but the remote SQL Server instance may not be configured for remote connections.
. By default, SQL Server Express is installed (configured) only for local connections.
. By default, MS SQL Server is installed (configured) for remote connections, but this might have been changed.
2. External Firewalls may filter out the communication between DS-Client and the target SQL server
3. Another applicaton is backing up SQL Server such maintainance jobs.
Workaround
Use the SQL "SQL Server Configuration Manager" tool:
1. Start > All Programs > Microsoft SQL Server > Configuration Tools > SQL Server Configuration Manager:
- Enable "TCP/IP and Named Pipes" for each of the instances you want to backup.
- Start the "SQL Browser" service on the remote server.
2. Configure the firewalls to allow outbound UDP traffic on port 1434 (port# for SQL Browser service) and TCP traffic on port 1433 (port# for default SQL Server instance)
3. Check the SQL Server Logs to confirm the other activities that are accessing the database beside Asigra. Disable the other activities