Redundant array of inexpensive disk （RAID）10 is known as the most reliable disk array architecture to tolerate up to half of total disk failures, but failure of two disks in the same mirror set still results in data...Redundant array of inexpensive disk （RAID）10 is known as the most reliable disk array architecture to tolerate up to half of total disk failures, but failure of two disks in the same mirror set still results in data loss. In this paper, we propose a new disk array architecture, mirroring and parity protected RAID （MP-RAID）, which combines both mirroring and parity techniques to further improve reliability of disk arrays. The main idea behind MP-RAID is to protect the data by both mirroring and parity techniques： keep two copies of data in the same mirror set and update the parity block in the log disk within the same parity groups. Reliability analysis shows that the reliability of MP-RAID, in terms of mean time to data loss （MTTDL）, is much better than RAID10 and RAID5.展开更多
In recent years,a lot of XOR-based coding schemes have been developed to tolerate double disk failures in Redundant Array of Independent Disks (RAID) architectures,such as EVENODD-code,X-code,B-code and BG-HEDP. Despi...In recent years,a lot of XOR-based coding schemes have been developed to tolerate double disk failures in Redundant Array of Independent Disks (RAID) architectures,such as EVENODD-code,X-code,B-code and BG-HEDP. Despite those researches,the decades-old strategy of Reed-Solomon (RS) code remains the only popular space-optimal Maximum Distance Separable (MDS) code for all but the smallest storage systems. The reason is that all those XOR-based schemes are too difficult to be implemented,it mainly because the coding-circle of those codes vary with the number of disks. By contrast,the coding-circle of RS code is a constant. In order to solve this problem,we develop a new MDS code named Latin code and a cascading scheme based on Latin code. The cascading Latin scheme is a nearly MDS code (with only one or two more parity disks compared with the MDS ones). Nev-ertheless,it keeps the coding-circle of the basic Latin code (i.e. a constant) and the low encod-ing/decoding complexity similar to other parity array codes.展开更多
One way to increase storage density is using a shingled magnetic recording(SMR)disk.We propose a novel use of SMR disks with RAID(redundant array of independent disks)arrays,specifically building upon and compared wit...One way to increase storage density is using a shingled magnetic recording(SMR)disk.We propose a novel use of SMR disks with RAID(redundant array of independent disks)arrays,specifically building upon and compared with a basic RAID 4 arrangement.The proposed scheme(called RAID 4SMR)has the potential to improve the performance of a traditional RAID 4 array with SMR disks.Our evaluation shows that compared with the standard RAID 4,when using update in-place in RAID arrays,RAID 4SMR with garbage collection not just can allow the adoption of SMR disks with a reduced performance penalty,but offers a performance improvement of up to 56%.展开更多
基金Project supported by the National Basic Research Program of China (Grant No.2004CB318201)the National High-Technology Research and Development Program of China (Grant No.2008AA01A401)the Changjiang Innovative Group of Ministry of Education of China (Grant No.IRT0725)
文摘Redundant array of inexpensive disk （RAID）10 is known as the most reliable disk array architecture to tolerate up to half of total disk failures, but failure of two disks in the same mirror set still results in data loss. In this paper, we propose a new disk array architecture, mirroring and parity protected RAID （MP-RAID）, which combines both mirroring and parity techniques to further improve reliability of disk arrays. The main idea behind MP-RAID is to protect the data by both mirroring and parity techniques： keep two copies of data in the same mirror set and update the parity block in the log disk within the same parity groups. Reliability analysis shows that the reliability of MP-RAID, in terms of mean time to data loss （MTTDL）, is much better than RAID10 and RAID5.
基金Supported in part by the National High Technology Re-search and Development Program of China (2008 AA01Z-401)the National Science Foundation of China (No.60903028)+1 种基金Doctoral Fund of Ministry of Education of China (20070055054)Science and Technology De-velopment Plan of Tianjin (08JCYBJC13000)
文摘In recent years,a lot of XOR-based coding schemes have been developed to tolerate double disk failures in Redundant Array of Independent Disks (RAID) architectures,such as EVENODD-code,X-code,B-code and BG-HEDP. Despite those researches,the decades-old strategy of Reed-Solomon (RS) code remains the only popular space-optimal Maximum Distance Separable (MDS) code for all but the smallest storage systems. The reason is that all those XOR-based schemes are too difficult to be implemented,it mainly because the coding-circle of those codes vary with the number of disks. By contrast,the coding-circle of RS code is a constant. In order to solve this problem,we develop a new MDS code named Latin code and a cascading scheme based on Latin code. The cascading Latin scheme is a nearly MDS code (with only one or two more parity disks compared with the MDS ones). Nev-ertheless,it keeps the coding-circle of the basic Latin code (i.e. a constant) and the low encod-ing/decoding complexity similar to other parity array codes.
文摘One way to increase storage density is using a shingled magnetic recording(SMR)disk.We propose a novel use of SMR disks with RAID(redundant array of independent disks)arrays,specifically building upon and compared with a basic RAID 4 arrangement.The proposed scheme(called RAID 4SMR)has the potential to improve the performance of a traditional RAID 4 array with SMR disks.Our evaluation shows that compared with the standard RAID 4,when using update in-place in RAID arrays,RAID 4SMR with garbage collection not just can allow the adoption of SMR disks with a reduced performance penalty,but offers a performance improvement of up to 56%.
