In this paper, we present an approach for software rejuvenation based on automated self-healing techniques that can be easily applied to off-the-shelf Application Servers and Internet sites. Software aging and transient failures are detected through continuous monitoring of system data and performability metrics of the application server. If some anomalous behavior is identified the system triggers an automatic rejuvenation action. This self-healing scheme is meant to be the less disruptive as possible for the running service and to get a zero downtime for most of the cases. In our scheme, we exploit the usage of virtualization to optimize the self-recovery actions. The techniques described in this paper have been tested with a set of open-source Linux tools and the XEN virtualization middleware. We conducted an experimental study with two applications benchmarks (Tomcat/Axis and TPC-W). Our results demonstrate that virtualization can be extremely helpful for software rejuvenation and fail-over in the occurrence of transient application failures and software aging.