Conventional tape backups are limited in their capability to support application recovery because they produce a single-point-in-time copy of the application data stored on secondary storage media. The recovery As tapes are overwritten, the ability to recover data to a specific point in time becomes more difficult. After two months, the best backup resolution will be at the previous month. After three weeks, the best resolution will be at the weekly level. You should be looking at online backups remote locations. It can actually be an other bulding of your network. I know I paid the price , when I had to server go down.