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VEE 2017
Sat 8 - Sun 9 April 2017 Xi'an, China
Sun 9 Apr 2017 10:45 - 11:15 at Zhu Que Room - Performance Chair(s): Paolo Bonzini

Storage consolidation in a virtualized environment introduces numerous duplications in virtual disks and imposes considerable pressure on disk I/O and caching. In this paper, we present a content look-aside buffer (CLB) approach for simultaneously providing redundancy-free virtual disk I/O and caching. CLB attaches persistent fingerprints to virtual disk blocks, which enables detection of I/O redundancy before disk access. At run time, CLB exploits content pages already present in the guest disk caches to service the redundant reads through page sharing, thus eliminating both redundant I/O requests and redundant disk cache copies. For write requests, CLB uses a group invalidating writeback protocol for updating fingerprints to support crash consistency while minimizing disk write overhead. By implementing and evaluating a CLB prototype on KVM hypervisor, we demonstrate that CLB delivers considerably improved I/O performance with realistic workloads. Our CLB prototype improves the throughput of sequential and random read on duplicate data by 4.1x and 26.2x, respectively. For typical read-intensive workloads, such as booting VM and launching application, CLB’s I/O deduplication and cache deduplication eliminates 94.9%-98.5% of the requests and saves 50%-100% cache memory in each VM, respectively. Compared with the QEMU’s raw virtual disk format, CLB improves the per-disk VM density by 8x-16x. For mixed read-write workloads, the cost of on-line fingerprint updating offsets the read benefit; nevertheless, CLB substantially improves overall performance.

Sun 9 Apr

10:45 - 12:15: Session 6 - Performance at Zhu Que Room
Chair(s): Paolo BonziniRed Hat, Inc.
vee-2017-Session-610:45 - 11:15
Chun YangPeking University, China, Xianhua LiuPeking University, China, Xu ChengPeking University, China
vee-2017-Session-611:15 - 11:45
Amanieu d'AntrasUniversity of Manchester, Cosmin GorgovanUniversity of Manchester, Jim GarsideUniversity of Manchester, John GoodacreUniversity of Manchester, Mikel Lujan
File Attached
vee-2017-Session-611:45 - 12:15
Min ZhuInstitute of Information Engineering, Chinese Academy of Sciences, Bibo TuInstitute of Information Engineering, Chinese Academy of Sciences, Wei WeiInstitute of Information Engineering, Chinese Academy of Sciences, Dan MengInstitute of Information Engineering, Chinese Academy of Sciences