OLRE: On-Line RAID Expansion for High-Throughput Cloud Storage

Abstract

Along with the development and application of Cloud Computing in recent years, Cloud Storage, as the module which provides data storage service in the Cloud Computing architecture, has become the kernel component of Cloud Computing. As the foundation of the whole storage system, the access performance of RAID plays the decisive role of the Cloud Storage performance. Cloud Storage must has the dynamic expansion capability to satisfy the rapid increase of data, however, the traditional RAID expansion is only adding physical disk and making simple data copy and the performance of expanded RAID still has a big space of ascension. At the same time, most RAID expansion mechanism need to pause the access and it could not be tolerated in Cloud Storage. In this paper, we put forward the design, implementation, and evaluation of OLRE, a on-line RAID expansion method which could satisfy high performance. OLRE perform RAID expansion when the part of disks in RAID is busy through monitoring I/O workload. And it also analysis the hot spot of data, and move them according to load balance. Eventually, improve the performance of the data access to achieve high throughput Cloud Storage systems effectively.