Using Persistent Memory To Reduce Cloud Servers Costs

By virtue of its very high speed, DDR memory is an important component of cloud servers. Such memory is expensive and forms a substantial portion of the total cost of ownership (TCO) of cloud servers. This disclosure describes techniques to selectively use persistent memory (PMEM) as a cheaper alternative to DDR to reduce cost. A hypervisor is modified to include components that perform smart management of virtualization in a cloud environment to achieve significant memory savings by managing the data placement policy, e.g., demoting cold data to PMEM and promoting hot data to DDR RAM. Such operation is achieved with minimal performance impact on the virtual machine and with no modifications to the guest operating systems or customer applications