Abstract
Green storage is a hot topic at the moment with the demand of physical storage devices increasing. Because of the data size increasing, conserving energy of storage systems is becoming a growing concern in current storage technology. The factors of disk power consumption include disk idle time, poor random writing performance and random read in distributed file systems. Hence, we present an adaptive write cache mechanism - CacheRAID. Redundant Arrays of Inexpensive Disk (RAID) is widely used in modern distributed storage systems. Our CacheRAID aims to improve the random access problems that implicitly exist in RAID techniques to create more idle time of hard drives, and conserve RAID disk array energy. Good reliability and space efficiency are quality requisites to a good fault tolerance mechanism. And there are some critical issues in fault tolerance system. First, how fast can fault tolerance system to rebuild their data block when storage system is failure? Then, the storage system is still recoverable under the upper bound limited of disk failure. For example, RAID system is usually recoverable when one disk is failed. On the other hand, the RAID storage system can’t rebuild itself when the numbers of failure disk are more than one. Finally, the space efficiency that is the trade of high fault tolerance factor. High fault tolerance usually need more data parity block, and these parities block will occupy much storage space in disk. Hence, how can we use less data to recovery our storage system? That is an important issue.