J. Li and C. Orji. I/O scheduling in tape-based tertiary systems. Journal of Mathematical Modelling and Scientific Computing, 6, 1996.  Home/Search   Document Not in Database   Summary   Related Articles   Check

.... are applicable only to specific applications such as video on demand [CPK95, KDST95] relational databases [ML95, SS93] and multidimensional arrays [SS94, CDK 95] Generally applicable techniques for reducing the access latency include scheduling of I O requests for a single medium [HS96, LO96, ABZ96] and altering the order in which media are loaded onto the drives [Ano96] Given the magnitude of the exchange time, it is generally assumed that reducing the number of media exchanges will always be beneficial. However, this assumption is not always valid, since there are instances where ....

....a batch of I O requests for a robotic library, we would like to determine whether schedules that minimize the media exchanges perform better than schedules that allow more exchanges to be made and if not, under which conditions do they not perform better. In contrast to previous studies [HS96, LO96] our study considers requests for more than a single medium. The rest of the paper is organized as follows. In Section 2 we summarize earlier work done on finding optimal schedules that minimize the number of media exchanges. In Section 3 an analytic evaluation of introducing extra media ....

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J. Li and C. Orji. I/O scheduling in tape-based tertiary systems. Journal of Mathematical Modelling and Scientific Computing, 6, 1996.

....library scheduling is that tertiary storage media such as tapes or optical disks are removable as opposed to fixed magnetic disks. The algorithms developed for disks all assume that the medium is never switched which is not true for robotic libraries. More recent work on tape scheduling [HS96b, LO96] has studied efficient processing schedules for I O requests for single tapes. In [HS96b] Hillyer and Silberschatz have analyzed algorithms for scheduling batched requests for a single serpentine tape that is loaded on the drive. Li and Orji [LO96] have studied efficient scheduling policies for ....

....More recent work on tape scheduling [HS96b, LO96] has studied efficient processing schedules for I O requests for single tapes. In [HS96b] Hillyer and Silberschatz have analyzed algorithms for scheduling batched requests for a single serpentine tape that is loaded on the drive. Li and Orji [LO96] have studied efficient scheduling policies for linear tapes. Both these studies do not consider scheduling requests for more than one medium. Sarawagi and Stonebraker have worked on the problem of ordering I O requests for tertiary storage media when tertiary storage is directly incorporated in ....

J. Li and C. Orji. I/O scheduling in tape-based tertiary systems. Journal of Mathematical Modelling and Scientific Computing, 6, 1996. 24

....is that tertiary storage media such as tapes or optical disks are removable as opposed to fixed magnetic disks. The algorithms developed for disks assume that all requests are located on the currently loaded medium which is not true for robotic libraries. More recent work on tape scheduling [HS96, LO96] has studied efficient processing schedules for I O requests for single tapes. In [HS96] Hillyer and Silberschatz have analyzed algorithms for scheduling batched requests for a single serpentine tape that is loaded on the drive. Li and Orji [LO96] have studied efficient scheduling policies for ....

....More recent work on tape scheduling [HS96, LO96] has studied efficient processing schedules for I O requests for single tapes. In [HS96] Hillyer and Silberschatz have analyzed algorithms for scheduling batched requests for a single serpentine tape that is loaded on the drive. Li and Orji [LO96] have studied efficient scheduling policies for linear tapes. Both these studies do not consider scheduling requests for more than one medium. Work has also been done on optimizing the performance of relational database management systems that incorporate tertiary storage [SS93, ML95, Sar95a, ....

[Article contains additional citation context not shown here]

J. Li and C. Orji. I/O scheduling in tape-based tertiary systems. Journal of Mathematical Modelling and Scientific Computing, 6, 1996.

....retrieval performance and disk space utilization for Write Once Read Many (WORM) optical disks is investigated. The placement of data on CLV optical disks in order to improve random I O based upon a hot cold distribution of accesses is studied in [FC91] More recent work on tape scheduling [HS96, LO96] has studied efficient processing schedules for I O requests for single tapes. In [HS96] Hillyer and Silberschatz have analyzed algorithms for scheduling batched requests for a single serpentine tape that is loaded on the drive. Li and Orji [LO96] have studied efficient scheduling policies for ....

....[FC91] More recent work on tape scheduling [HS96, LO96] has studied efficient processing schedules for I O requests for single tapes. In [HS96] Hillyer and Silberschatz have analyzed algorithms for scheduling batched requests for a single serpentine tape that is loaded on the drive. Li and Orji [LO96] have studied efficient scheduling policies for linear tapes. Both these studies do not consider scheduling requests for more than one medium. Work has also been done on optimizing the performance of relational database management systems that incorporate tertiary storage [SS93, ML95, Sar95a, ....

J. Li and C. Orji. I/O scheduling in tape-based tertiary systems. Journal of Mathematical Modelling and Scientific Computing, 6, 1996.

....function considered is the makespan or total time to service all requests, then the scheduling problem is very similar to the well known Traveling Salesperson Problem. However, this is not the case when considering the average waiting time, as in our problem. Recent work on tape scheduling [3, 4] has studied efficient processing schedules for I O requests for single tapes. In [3] Hillyer and Silberschatz have analyzed algorithms for scheduling batched requests for a single serpentine tape that is loaded on the drive. Li and Orji [4] have studied efficient scheduling policies for linear ....

....as in our problem. Recent work on tape scheduling [3, 4] has studied efficient processing schedules for I O requests for single tapes. In [3] Hillyer and Silberschatz have analyzed algorithms for scheduling batched requests for a single serpentine tape that is loaded on the drive. Li and Orji [4] have studied efficient scheduling policies for linear tapes. Both these studies do not consider scheduling requests for more than one medium. Work has also been done on optimizing the performance of relational database management systems that incorporate tertiary storage [7, 12] It has been ....

J. Li and C. Orji. I/O scheduling in tape-based tertiary systems. Journal of Mathematical Modelling and Scientific Computing, 6, 1996.

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