Sharif Digital Repository

Deduplication is a data reduction technique, which eliminates redundant data by storing only a single copy of each file or block, along with a reference to the unique copy of data. Deduplication reduces the storage space and bandwidth requirements of data storage systems, and becomes more effective when applied across multiple users. All deduplication techniques use cryptographic algorithms to detect duplication instead of byte-by-byte comparison between input data and all previously stored data. In this manner, the data stream is divided into non-overlapping chunks of data. Then, the hash values of non-overlapping chunks create an exclusive criterion to identify duplicates. In this thesis,... 

Storage is well-known as the performance bottleneck in I/O intensive programs such as online transaction processing applications; thus designing a cost-effective high performance disk subsystem is a major concern in enterprise applications. Data tiering is an efficient way to optimize cost, performance, and reliability in storage servers. With the promising advantages of Solid State Drives (SSDs) over Hard Disk Drives (HDDs) such as lower power consumption and higher performance , traditional data tiering techniques should be revisited in order to use SSDs in a more efficient way. This thesis presents a data tiering technique at the Operating System (OS) level to enhance system performance...