There are obvious bad choices such as keeping backup media on a different floor of the same building or even in a neighboring building. That said, it might be acceptable in a particular area to have backup tapes stored in a vault a few city blocks away from the data center. In other areas, such as hurricane-prone regions, the tapes must be kept at a distance greater than the destructive reach of the weather phenomenon.
The bottom line is that backup tapes should be kept at a safe distance from the disruptive or destructive elements that may cause you to need those tapes. Best practices would dictate that a risk assessment be conducted to identify the threats, probabilities and impact. This information can then be used to establish the appropriate distance between production and backup data.
This was first published in September 2005