Live migration of virtual machines is an important component of the emerging cloud computing environments. Migrating operating system instances across distinct physical hosts is a useful tool for administrators of data centres and clusters. Hence, a key issue in live migration is the total migration time and the downtime. To improve the performance of live migration, an optimized iterative pre-copy algorithm is used to reduce the dirty rate of VM. WSClock page replacement algorithm has been proposed along with traditional pre-copy approach that includes pre-processing phase for reducing the amount of transferred memory page and total migration time.