Large enterprises generally have redundancy mechanisms in place for critical SQL databases and are managed by an IT staff.  For those without the large IT staff to manage your systems, you may still need something more than nightly backups.  For high-availability without high cost,  SQL Server 2005 Standard and Enterprise Edition introduced database mirroring support.  Using a passive SQL Server to mirror the DBXL database, you can obtain high-availability without the need for an additional SQL Server license.  The SQL instance can be on an existing or new server (including VMs) with sufficient resources to host the database.   Just remember when using VMs, that failovers should reside on different physical hosts.  For additional information, refer to SQL Server 2005 Books Online topic “Overview of Database Mirroring”.

SQL Server 2005 Workgroup does not support database mirroring but does support transaction log shipping, which is similar to asynchronous database mirroring.  For additional information, refer to SQL Server 2005 Books Online topic “Understanding Log Shipping”.

Additional licensing information can be obtained here.

Note: Qdabra DBXL has not been tested with automatic failover and may require manual failover configuration.