HMDC: Live Virtual Machine Migration Based on Hybrid Memory Copy and Delta Compression

Live VM (virtual machine) migration has become a research hotspot of virtualized cloud computing architecture. We present a novel migration algorithm which is called HMDC. Its main idea includes two parts. One is that it combines memory pulling copy with memory pushing copy to achieve hybrid memory copy. The other one is that it uses a delta compression mechanism during dirty pages copy, in which source host makes use of memory cache to get XOR delta pages, and then compresses delta pages which are easy to compress by the XOR binary RLE (run-length encoding) algorithm. Source host transmits delta compression pages instead of dirty pages to target host. HMDC increases throughput and decreases total migration data by using delta compression and thus to achieve dirty pages copy quickly. The experimental results demonstrate that HMDC evidently reduces total migration time, VM downtime and total migration data compared with Pre-copy and XBRLE algorithm. It makes the process of memory migration more high-effective