Efficient data cluster management scheme for Qcow2-based virtual disk in home cloud server

Nowadays, home cloud servers have adopted virtualization technologies to fully utilize their own computing resources. In this paper, we introduce a novel data cluster management scheme for qcow2-based virtual disk to improve I/O performance and storage space efficiency of the home cloud server. Our scheme aims to mitigate the sync amplification problem of qcow2 format, caused by allocating data clusters in a grow-only manner. To achieve the goal, we try to reuse the allocated data clusters that are no longer in use. Our experimental results show that our scheme improves I/O performance and reduces the number of sync operations, by up to 52.7% and 59.8%, respectively, compared with the conventional scheme.