As a database administrator, it is your responsibility to be concerned about anything that might affect the stability of your systems. In that vein, it is not enough to back up your database regularly. You must also check regularly that the restore process works. In the optimum situation, a second machine is kept constantly up to date with a regularly scheduled process of transaction backups and restores. In most cases, the cost of the extra hardware is easily justified when compared to the cost to the business of the downtime that will be incurred in the event of a crash without a hot backup. Additionally, the second machine can sometimes do double duty as a reporting server for running reports that are too intensive to be executed on the production system.