支持无冗余 I/O 和缓存的数字指纹虚拟磁盘技术

Storage consolidation in a virtualized environment introduces tremendous duplications on virtual disks and imposes a great pressure on the disk I/O and caching. In this paper, we present the Fingerprinted Virtual Disk (FVD) approach to provide redundancy-free disk I/O and caching over virtual disks. FVD introduces persistent fingerprints for virtual disk blocks to enable I/O redundancy detection before accessing the disk, and exploits the content pages that already in guest caches to service the redundant I/O requests by page sharing. By implementing and evaluating a prototype of FVD on the KVM hypervisor, we demonstrate that our FVD prototype improves the sequential and random read throughput on duplicate data from 122 MB/s to 430 MB/s and from 45 MB/s to 368 MB/s, respectively. Meanwhile, the overhead on fresh sequential reads is only 0.3%, and the writing overhead for maintaining persistent fingerprints is 9.4%. Our experimental results also show that the average booting time of 1 to 16 simultaneously running Linux VMs is almost constant near 38s with FVD, while the booting time increases rapidly to 178s without FVD. For 8 Windows VMs, the booting time is accelerated by 65.1% with FVD, and the time to launch office applications is accelerated by 168.0%.