A very expensive EHR installation crashed with major implications as reported by HealthcareIT News. These are huge systems for large Organizations such as Sutter Health of Northern California. But there is a lesson for small practices, even solo docs.
It is, that don't try to do everything in-house, don't try to be technologists, don't buy a 'Client Server' system. Fortunately, there are really good Web based EMR system.
If you are concerned about 'what is my internet connection goes down', I can tell you, there are plenty backup options out there, but if your server goes down, you are sc#$@%^.