Les:

You are quite right in stating that at least one backup has to be off-site. The issue is how far off-site is enough. Having a rotation plan for the backup device and having a trusted employee take the most recent backup home each day, is sufficient to protect against system failure, fire, flood, etc. Of course, if a disaster wipes out the whole city, that won’t help, but I would suspect you would then have more urgent problems!

Note: I recommend a separate backup of the accounting data – often to a USB flash drive – for ease of restore. I often find that the accounting staff has no idea how to restore selected files from a network backup and the network manager has no idea what files accounting is looking for. Again, rotate several drives and have at least one off site.

Here is another take on disaster recovery: find a company in your city that is not a competitor and is running the same operating system (and perhaps software) as you. Work together to co-ordinate backup methods/devices and agree to leave enough room on your systems to, in an emergency, run the other company’s processes for a short time. I know a case where this is being done with mainframe systems,