Technology refresh is an important component in data center management. The goal of this paper is to assess the impact of HW and OS currency on server availability based on a large set of incident tickets and server attributes data collected from several different IT environments. In order to achieve this we first identify the server failure incidents using a machine learning method for automatic ticket classification. Then we conduct the data analysis to inspect the impact of HW and OS type along with their currency on the rates of server failures. This can further be used to derive guidelines to support the technology refresh decisions in the data centers.