A Method for Improving Concurrent Write Performance by Dynamic Mapping Virtual Storage System Combined with Cache Management

The paper presents a new dynamic mapping virtual storage system, which is characterized by: (a) distribute storage resources according to need, thus improving storage resource utilization, (b) more fundamentally, through write-anywhere pattern to sequentialize concurrent write requests by dynamic address mapping mechanism, thus improving concurrent write performance for applications. Meanwhile, taking into account imperfection small size write requests handling and the negative impact on read performance, we combine the system with CBD system which is responsible for optimizing cache management. We have implemented our virtual storage system in Linux kernel 2.6.18 as a pseudo device driver. The experiment results show that concurrent write bandwidth approaches raw disk write performance. And in 64-stream concurrent write case, E-ASD can outperform concurrent write bandwidth of LVM by up to 160%, and its max single-stream read loss is less than 25% compared to LVM, with concur-rent read performance close to each other. Read performance still has space to be improved given larger cache and proper prefetching.