If you manage multiple servers, and you don't have complete control over your database backups, then you need to be checking regularly that all of your databases are indeed being backed up. With SQL Server 2008, Policy Based Management makes this very easy to do. There is a Microsoft Books Online entry for this:
You don't have to be on a SQL Server 2008 server to use PBM. You can actually use it manually from SQL Server Management Studio by downloading the Express Edition of 2008 with Tools. However, if you are not taking the leap to SQL Server 2008 anytime soon, you still need to know how to monitor this. You can do so with a simple TSQL Query using a few system tables:
I intentionally use the legacy table sysdatabases table so that this script works across all platforms exactly the same way. If you were to download the Express Edition of SQL Server 2008 Management Studio, you could hit all of your SQL Servers regardless of edition, (2000, 2005 and 2008) with this on a multi-server query. Want to know how to do that, see my article on this
SELECT database_name, last_backup
SELECT database_name, MAX(backup_finish_date) [last_backup]
JOIN MASTER..sysdatabases d ON database_name = d.name
WHERE TYPE = 'd'
GROUP BY database_name
SELECT d.name, NULL
FROM MASTER..sysdatabases d
WHERE NOT EXISTS (
WHERE d.name = database_name)
) AS tab
WHERE tab.last_backup < GETDATE()-14
OR tab.last_backup IS NULL
I know that is kind of a shameless plug, but it is what it is.