Content addressable storage （CAS） is a promising technology for improving storage efficiency as well as access throughput. Currently, many CAS products are implemented on the block level, which results in loss of fi...Content addressable storage （CAS） is a promising technology for improving storage efficiency as well as access throughput. Currently, many CAS products are implemented on the block level, which results in loss of file information. Thus, some sophisticated optimizations cannot be achieved, such as accurate fileprefetching. This paper presents a file-aware block-level storage system combined with the CAS function. In contrast with some existing file-level CAS, this system is transparent to upper-level applications, including the operating system and the file system. These features are achieved by using smart-disk technologies to help the storage system to learn the file-system layout. A prototype was implemented on an open-source virtual machine （VM） with the vip operating system being Windows XP. Tests show that this combination significantly reduces the size of the VM image file and improves the storage performance by discarding unused blocks and using a simple file-level prefetching strategy.展开更多
基金Supported by the National Natural Science Foundation of China(No. 60773147)the National High-Tech Research and Development (863) Program of China (No. 2006AA01Z111)the Basic Research Foundation of Tsinghua National Laboratory for Information Science and Technology (TNList)
文摘Content addressable storage （CAS） is a promising technology for improving storage efficiency as well as access throughput. Currently, many CAS products are implemented on the block level, which results in loss of file information. Thus, some sophisticated optimizations cannot be achieved, such as accurate fileprefetching. This paper presents a file-aware block-level storage system combined with the CAS function. In contrast with some existing file-level CAS, this system is transparent to upper-level applications, including the operating system and the file system. These features are achieved by using smart-disk technologies to help the storage system to learn the file-system layout. A prototype was implemented on an open-source virtual machine （VM） with the vip operating system being Windows XP. Tests show that this combination significantly reduces the size of the VM image file and improves the storage performance by discarding unused blocks and using a simple file-level prefetching strategy.
