Drapeau, Katz H. Striped Tape Arrays. Proceedings of 12th IEEE Mass Storage systems Symposium, p.257-265, 1993.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....intervals from a tape is studied in [32] assuming that block retrievals for separate intervals cannot be interleaved, that blocks for overlapping intervals are not cached for reuse, and that locate time is proportional to the di erence in block numbers. Striped tape organizations are modeled in [33, 34, 35, 36]. Database algorithms for systems that incorporate both tape and disk are studied in [37] and issues of caching, query optimization, and mount scheduling for relational databases using tape jukeboxes is studied in [38, 39] The problem of optimal data placement for di erent tape library ....

A. L. Drapeau and R. H. Katz, \Striped tape arrays," in Proceedings of the Twelfth IEEE Symposium on Mass Storage Systems, (Monterey, CA), pp. 257-265, Apr. 1993.

....the idea is to keep the processors as close to the data as possible. Unfortunately, the same type of parallelism as with disks is not possible due to costs: disks cost approximately 1000 per Gigabyte; high performance tape approximately 100,000 per unit. Although RAID style tape offers some hope [7], in the near future some type of multi level caching system is needed to achieve this level of scalability. 5 5.2 Design 6 Segment Cache Manager 6.1 Background Briefly, in our design, large size folios are accessed from tape, or more generally a hierarchical storage system, and cached to a ....

A. L. Drapeau and R. H. Katz, "Striped Tape Arrays," IEEE Press, Los Alamites, 1993, pp. 257--265.

.... optimizations has been published (unlike the case with magnetic disk storage see [ReWi94] A list of the published works known to the author are: Christodoulakis and Ford [CF88] Christodoulakis [Ch87] Chinnaswamy [Ch92] Finestead and Yeager [FY92] Hull and Ranade [HR93] Drapeau and Katz [DK93], Hillyer and Silberschatz [HS96] Even among the above works, the data and the models are generally not sufficiently detailed to permit modeling and optimization. The exceptions ( DK93] with read throughput characterizations, HS96] with seek times) do not provide a model of an entire system, ....

....[Ch87] Chinnaswamy [Ch92] Finestead and Yeager [FY92] Hull and Ranade [HR93] Drapeau and Katz [DK93] Hillyer and Silberschatz [HS96] Even among the above works, the data and the models are generally not sufficiently detailed to permit modeling and optimization. The exceptions ([DK93] with read throughput characterizations, HS96] with seek times) do not provide a model of an entire system, and instead provide information about only one part. Contributions of this article We spent a week at NASA Goddard Space Flight Center to measure the performance characteristics of two ....

A. Drapeau and R.H. Katz. Striped Tape Arrays. In Proc. 12th IEEE Mass Storage Systems Symposium pages 257-265 1993.

.... servicing a request as the time between the request s arrival to the time the system initiates the reading of the object (from a disk) the additional delay until data is actually delivered to the display 2 The seek latency for a 1:3GB tape on a 1000 tape drive can be on the order of 20 seconds [7], whereas a similarly priced disk, of a similar capacity, has a maximum seek time on the order of 35 milliseconds and more than 16 times the transfer rate. Tape systems with significantly higher transfer rates and tape capacities although not with much lower seek latency do exist, but at a cost ....

A. L. Drapeau and R. Katz. Striped Tape Arrays. In Proc. of the 12th IEEE Symposium on Mass Storage Systems, pages 257--265, Monterey, California, April 1993.

....temporal database[5] They also tried to rearrange the fragments to reduce the seek length. B. K. Hillyer et al. described I O scheduling algorithms for serpentine tape drives[6] Striping techniques applied to tape archivers for the improvement of bandwidth were explained by A. L. Drapeau et al.[7] and L. Golubchik et al.[8] We proposed a partial migration scheme to move only a necessary part of a file from a tertiary storage[9] There are several studies on optimization of tertiary file accesses. As mentioned above, tape migration mechanisms plays a very important role for both hot ....

A. L. Drapeau and R. H. Katz. "Striped tape arrays". In Proceedings of Twelfth IEEE Symposium on Mass Storage Systems, pages 257--265, Montrey, California, April 1993.

....lost data can be reconstructed from the nonfailed data and the data stored on the parity disk. We note that there are many variations on the choice of parity disk for a given stripe of data blocks. When RAID technology is applied to tapes, it becomes RAIT (Redundant Arrays of Inexpensive Tapes) [2]. User data is written to N tapes, and an additional tape stores parity blocks (e.g. RAID level 4) A discussion of RAIT products can be found on line [5] and vendors who sell RAIT products can be found by asking a web search engine for pages that include the word RAIT . RAIT technology has ....

A. Drapeau and R. Katz. Striped tape arrays. In Proc. 12th IEEE Mass Storage Systems Symposium, pages 257--265, 1993.

....via a high speed bus or network [3,9,20] I O parallelism in these systems is achieved by striping data across several storage nodes devices. A more general framework for parallel disk I O is provided by arrays of disks [7,8,14,16] which are now quite common. Tape arrays have also been studied [5] and have found use in backup systems with high bandwidth requirements. Concurrent access to a mixture of device types, disks and tapes, has received little attention from the operating system and database communities. Most studies in the relational database literature, for instance, consider ....

A. L. Drapeau and R. H. Katz. Striped tape arrays. In Proc. IEEE Symp. Mass Storage Systems, pages 257--265, Monterey, CA, Apr. 1993.

....block size) b 3 ; hence at any time the maximum bandwidth the tertiary storage level can deliver, denoted by tertiary bandwidth B 3 , is given by b 3 N (3) dr . A number of tertiary drives can be configured as if they form a single drive (similar to a disk array) through fine grained striping [24, 25]. In this way, the bandwidth of the drives can be used in parallel to deliver a file and hence delivery bandwidth of a file is increased. As the drives are no longer independent in this case, it is as if N (3) dr = 1. Such a configuration achieves maximal bandwidth parallelism (using all the ....

A. Drapeau and R. Katz, "Striped Tape Arrays," in IEEE Symposium on Mass Storage Systems, pp. 257--265, 1993.

....as an archival medium or in a near line system for storing data for which time to first access is not critical. Finally, optical tape has been identified [17] as a promising technology for near line storage systems. Striping techniques for robotic tape libraries are also the focus of much research [9, 8, 14] and offer the potential for improved response time for large data transfers. We note that references [17, 28] contain excellent surveys on storage technologies. In addition, reports on trends in mass storage markets and technologies are available from [22, 21] 2.2.2 High Performance Channels ....

Ann L. Drapeau and Randy Katz. Striped Tape Arrays. In Proceedings of the 12th IEEE Symposium on Mass Storage Systems, pages 257--266, Monterey, CA, April 1993.

....512 KB for a Quantum DLT4000 tape drive. Their results, however, do not apply to continuous data in which chunk size must be in the order of tens or even hundreds of MB, i.e. a continuous object consists of several GB of data compared to a typical satellite image of about a 100 MB. 7 Striping [DK93] and [GMW95] considered robotic storage libraries, analyzing the performance and trade off of striping large files on several tapes. Both studies deal with non continuous large data files in which no transfer alternation and synchronization is necessary under their framework, finding that striping ....

Drapeau, A., and Katz, R., "Striped Tape Arrays," in Proceedings of the 12 th IEEE Symposium on Mass Storage Systems, Monterey, CA, April 1993.

....the RAID technology [13] to increase the bandwidth of inexpensive disks, as well as in application specific systems, such as multimedia storage servers [2] to meet the high bandwidth demands of display stations. Therefore, it is natural to attempt to extend this idea to a tape storage system. In [8], the authors examine the performance of striped magnetic tape libraries. They consider a closed simulation model with a workload consisting of fairly small (under 1 GB) reads (75 ) and writes (25 ) of a constant size, within an individual simulation run. The striping configuration is analogous to ....

A. L. Drapeau and R. Katz. Striped Tape Arrays. In Proc. of the 12th IEEE Symposium on Mass Storage Systems, pages 257--265, Monterey, California, April 1993.

....in tape storage [9, 18, 2] A reference model for hierarchical storage appears in [3] and [10, 6] discuss the role of hierarchical storage management in video on demand systems. 11] presents a logstructured filesystem that spans disk and tape storage. Striped tape organizations are studied by [4, 7]. 14] describes join algorithms for databases stored partly on tape and partly on disk, and [16, 17] deals with issues of caching, query optimization, and mount scheduling for relational database use of tertiary storage jukeboxes. To our knowledge, no prior publications present a realistic model ....

Drapeau, A. L., and Katz, R. H. Striped tape arrays. In Proceedings of the Twelfth IEEE Symposium on Mass Storage Systems [1], pp. 257--265.

....on optimizing for cost per display. It is possible to extend our configuration planner to consider other application requirements, such as initial latency and storage reliability. For example, we expect that storage reliability to be inversely proportional to the data access from tertiary devices [5], and, hence, tape devices should be accessed less frequently. Second, we plan on studying the effects of a changing data access pattern and database size on the optimal configuration. Finally, we plan on studying the performance effects of data placement on tapes. Acknowledgments We thank the ....

A. L. Drapeau and R. H. Katz. Striped Tape Arrays. In Proceedings of the Twelfth IEEE Symposium on Mass Storage Systems, April 1993.

....to the drive service time variance. Rewind time The rewind time is time period after the last file has been transferred from the media and the media can be ejected to the robot arm (it is typical to rewind tapes after use to ensure longevity, hence the name) The rewind time is device dependent [15], so we require that the mean and variance of the rewind time be supplied as parameters. Transfer time Given that a file of Sz bytes is to be transferred, a commonly accepted model of the transfer time is a simple linear model: T xf = a Sz=X b where T xf is the transfer time, X b is the transfer ....

....times are difficult enough [34] The problem is compounded by the random seek distances, disk vs. single pass vs. serpentine tape, and fast seek modes. One simple model is to assume that files are randomly distributed across a single pass tape. Suppose that f files are to be transferred. Then [15]: E seek (f) f f 1 T fs fT stl M 2 seek (f) fT fs = f 2) 2f 2 T stl T fs = f 1) f 2 T fs Our solver assumes that user supplies a function which takes the number of files f as parameter and returns the mean and the second moment of the seek time. The unconditional seek time ....

A. Drapeau and R.H. Katz. Striped tape arrays. In Proc. 12th IEEE Mass Storage Systems Symposium, pages 257--265, 1993.

.... for scheduling its reading from the disks, or c) insufficient disk storage, i.e. the object in question may not be disk resident and hence may have to be retrieved from tertiary storage before it can 2 The seek latency for a 1:3GB tape on a 1000 tape drive can be on the order of 20 seconds [7], whereas a similarly priced disk, of a similar capacity, has a maximum seek time on the order of 35 milliseconds and more than 16 times the transfer rate. Tape systems with significantly higher transfer rates and tape capacities although not with much lower seek latency do exist, but at a cost ....

A. L. Drapeau and R. Katz. Striped Tape Arrays. In Proc. of the 12th IEEE Symposium on Mass Storage Systems, pages 257--265, Monterey, California, April 1993.

....Video popularity is measured by its access frequency, while the heat (temperature) of a library is measured by the total of the access frequency of its tapes. Drapeau and Katz extends the idea of RAID to tape drives in a library system so as to improve the performance of a tertiary system [62]. They consider striping data among the tapes so that tape bandwidth can be used in parallel, but with an increase in exchange latency. They show that, given a certain stripe size, when the load is low and the requested data size is large, striping improves the performance of the system; while ....

.... independently, hence achieving high request concurrency (serving multiple requests at the same time) but low bandwidth parallelism (using all the bandwidths at the same time) They can also be configured as if they formed a single drive (similar to a disk array) through fine grained striping [62, 63]. In this way, the bandwidth of the drives can be used in parallel to deliver a file and hence the delivery bandwidth of a file is increased. As the drives are no longer independent in this case, it is as if N (3) dr = 1. Such paralleldrive configuration achieves maximal bandwidth parallelism ....

[Article contains additional citation context not shown here]

A. Drapeau and R. Katz, "Striped tape arrays," in Proceedings of IEEE Symposium on Mass Storage Systems, pp. 257--265, 1993.

....et al. in [15] consider a system of multiple libraries and propose using a migration wagon to move tapes from one library to another in order to achieve load balancing. Golubchik et al. Drapeau and Katz, and Ford et al. apply the idea of RAID to library systems to improve its performance [16] [17], 18] Lau and Lui in [19] investigate the influence of the tape block size in a library on user delay for continuous media. Tertiary level was discussed in the context of a hierarchical system as early as 1978 [20] Misra in [21] analyzes IBM 3850 hierarchical storage system using a closed ....

A. Drapeau and R. Katz, "Striped tape arrays," in Proceedings of IEEE Symposium on Mass Storage Systems, pp. 257--265, 1993.

....tertiary storage devices in common use tape and optical disk. Both of these are high density removable media. The tradeoffs between the two media are presented in Table 1. Two types of magnetic tape, helical scan and longitudinal (linear) scan, are presented. The numbers for the tapes come from [4], while the optical disk statistics come from [16] Table 1 includes figures for the IBM 3490 and the Ampex D 2. Currently, the IBM 3480 tape format is standard at most supercomputer installations, though some are beginning to move to helical scan tapes that provide higher density. The IBM 3480 ....

Ann L. Drapeau and Randy H. Katz. "Striped tape arrays." In Digest of Papers. Twelfth IEEE Symposium on Mass Storage Systems, 1993. To appear.

No context found.

Ann L. Drapeau and Randy H. Katz. Striped tape arrays. In Digest of Papers. Twelfth IEEE Symposium on Mass Storage Systems, April 1993.

No context found.

Drapeau, Katz H. Striped Tape Arrays. Proceedings of 12th IEEE Mass Storage systems Symposium, p.257-265, 1993.

No context found.

A. L. Drapeau and R. H. Katz. Striped Tape Arrays. In Proceedings of the Twelfth IEEE Symposium on Mass Storage Systems, April 1993.

No context found.

A. L. Drapeau and R. Katz. Striped Tape Arrays. In Proc. of the 12th IEEE Symposium on Mass Storage Systems, pages 257--265, Monterey, California, April 1993.

No context found.

A. Drapeau and R. H. Katz, "Striped Tape Arrays," Proceedings of the 12th IEEE Mass Storage Systems Symposium, 1993, pages 257 - 265.

No context found.

Ann L. Drapeau and Randy H. Katz. Striped tape arrays. Technical report, UC Berkeley, 1993.

No context found.

Ann L. Drapeau and Randy H. Katz. Striped Tape Arrays. In Digest of Papers. Twelfth IEEE Symposium on Mass Storage Systems, April 1993.

First 50 documents

Online articles have much greater impact   More about CiteSeer.IST   Add search form to your site   Submit documents   Feedback  

CiteSeer.IST - Copyright Penn State and NEC