Based on pay-as-per-usage policy, there is a tremendous use of cloud computing in scientific society like bio-medical, healthcare and online financial applications. Fault tolerance is one of the biggest challenges to guarantee the reliability and availability of critical services. We must make the system to avail by minimizing the impact of failure. In this paper, we conducted a comparative analysis of various approaches for tolerating faults through scheduling in cloud computing environment based on their policies. The goal of this paper is not only used to analyze the existing methods, but also to identify the areas needed for future research.