High Performance RAIT
摘要
The ability to move 10s of TeraBytes in reasonable amounts of time are critical to many of the High Energy Physics applications.This paper examines the issues of high performance,high reliability tape storage systems,and presents the results of a 2-year ASCI Path Forward program to be able to reliably move 1GB/s to an archive that can last 20 years.This paper will cover the requirements.approach,hardware,application software,interface descriptions,performance,measured reliability and predicted reliability.This paper will also touch on future directions for this research.The current research allows systems to sustain 80MB/s of uncompressable data per Fibre Channel interface which is striped out to 8 or more drives.This looks to the application as a single tape drive from both mout and data transfer perspectives .Striping 12 RAIT systems together will provide nearly 1GB/s to tape.The reliability is provided by a method of adding parity tapes to the data stripes.For example,adding 2 parity tapes to an 8-stripe group will allow any 2 of the 10 tapes to be lost or damaged without loss of information.The reliability of RAIT with 8 stripes and 2 parities exceeds that of mirrored tapes while RAIT uses 10 tapes instead of the 16 tapes that a mirror would require.The results of this paper is to be abloe to understand the applicability of RAIT and to be able to understand when it may be useful in High Energy Physics applications.