At first glance, disaster recovery and business continuity may sound like the same thing. In a sense, they are, because their real difference is a matter of scale.

Disasters are just that: disasters. Full-blown events that pick up your company and drop it on the ground like it was a toy (sometimes, quite literally). But business continuity is something you need for subtler, yet just as important events, like a downed payroll server, or a file getting deleted that brings your web server to a screeching halt.

For situations like this, business continuity appliances (BCAs) are a very appropriate solution. What BCAs do, simply, is clone whatever servers to which you attach them. If it’s a physical BCA, typically you just attach the device to the network, point it at the desired machines and off you go. Virtual appliances, such as those offered by VMware, comport themselves in much the same manner.

Brian Proffitt is a veteran technology journalist, analyst, and author with experience in a variety of technologies, including cloud, virtualization, and consumer devices. Follow him on Twitter @TheTechScribe and Google+ at +Brian Proffitt.

BCAs are pretty much set-it-and-forget-it devices, able to clone away with little to no management needed. It’s important to remember, though, that BCAs are not meant to be disaster recovery devices. They’re meant to handle the foibles in a workplace that can ruin someone’s or, in some cases, bring the business to a standstill.

BCAs are located on-site, typically, and as such make poor disaster recovery tools. Businesses who rely on them for this purpose are just asking for trouble. Better to have firm disaster recover plan in place, independent of any BCAs. (See our chart below for some sample products in this space.)

Also, like disaster recovery, the use of BCAs will need to be planned. Since IT funding is limited, you can’t just plug these devices willy-nilly into your network. Prioritize what applications and servers needs to have the highest level of business continuity, and implement on those objectives.

Virtual BCAs can, or course, mitigate the costs of any business continuity plan. With lower power, space, and hardware overhead, virtual BCAs may be just the solution your organization needs.

Business continuity, when implemented properly, can be just the thing to get you out of a jam when system availability is a business-critical need, even without disasters.