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Consider a disk that has 209 cylinders, starting from index 0. At some time, the disk arm is at the 57th cylinder from the end moving from largest to innermost cylinder. There is a queue of disk access requests for cylinders 5, 40, 75, 195, 145, 203, 106 and 122. The R/W head of the disk uses the Circular Scan algorithm to reach the disk and access the data. The disk arm requires 1 msec to move between adjacent cylinders and 9 msec to move between the largest and innermost cylinder. The total seek time is _______.
Correct answer is '2036'. Can you explain this answer?
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Consider a disk that has 209 cylinders, starting from index 0. At some...
Given:
- Disk has 209 cylinders, starting from index 0.
- Disk arm is at the 57th cylinder from the end.
- Disk arm is moving from the largest to innermost cylinder.
- Disk access requests queue: 5, 40, 75, 195, 145, 203, 106, 122.
- Disk arm requires 1 msec to move between adjacent cylinders.
- Disk arm requires 9 msec to move between the largest and innermost cylinder.
To Find:
Total seek time.
Solution:
To calculate the total seek time, we need to consider the movement of the disk arm from its current position to each requested cylinder.
1. Calculate the total seek time for the requests before the current position:
Since the disk arm is moving from the largest to innermost cylinder, we need to calculate the seek time for the requests that are larger than the current position.
- 195: The disk arm needs to move from cylinder 209 to 195, which requires 9 * (209 - 195) = 126 msec.
- 203: The disk arm needs to move from cylinder 209 to 203, which requires 9 * (209 - 203) = 54 msec.
Total seek time for the requests before the current position = 126 + 54 = 180 msec.
2. Calculate the total seek time for the requests after the current position:
Since the disk arm is moving from the largest to innermost cylinder, we need to calculate the seek time for the requests that are smaller than the current position.
- 145: The disk arm needs to move from cylinder 209 to 0 and then from 0 to 145, which requires 9 * (209 + 145) = 3342 msec.
- 122: The disk arm needs to move from cylinder 209 to 0 and then from 0 to 122, which requires 9 * (209 + 122) = 3105 msec.
Total seek time for the requests after the current position = 3342 + 3105 = 6447 msec.
3. Calculate the total seek time for the requests between the current position and the largest cylinder:
Since the disk arm is moving from the largest to innermost cylinder, we need to calculate the seek time for the requests that are between the current position and the largest cylinder.
- 75: The disk arm needs to move from cylinder 209 to 0 and then from 0 to 75, which requires 9 * (209 + 75) = 2700 msec.
- 106: The disk arm needs to move from cylinder 209 to 0 and then from 0 to 106, which requires 9 * (209 + 106) = 4149 msec.
Total seek time for the requests between the current position and the largest cylinder = 2700 + 4149 = 6849 msec.
4. Calculate the total seek time for the requests between the current position and the innermost cylinder:
Since the disk arm is moving from the largest to innermost cylinder, we need to calculate the seek time for the requests that are between the current position and the innermost cylinder.
- 40: The disk arm needs to move from cylinder 57 to 40, which
- Disk has 209 cylinders, starting from index 0.
- Disk arm is at the 57th cylinder from the end.
- Disk arm is moving from the largest to innermost cylinder.
- Disk access requests queue: 5, 40, 75, 195, 145, 203, 106, 122.
- Disk arm requires 1 msec to move between adjacent cylinders.
- Disk arm requires 9 msec to move between the largest and innermost cylinder.
To Find:
Total seek time.
Solution:
To calculate the total seek time, we need to consider the movement of the disk arm from its current position to each requested cylinder.
1. Calculate the total seek time for the requests before the current position:
Since the disk arm is moving from the largest to innermost cylinder, we need to calculate the seek time for the requests that are larger than the current position.
- 195: The disk arm needs to move from cylinder 209 to 195, which requires 9 * (209 - 195) = 126 msec.
- 203: The disk arm needs to move from cylinder 209 to 203, which requires 9 * (209 - 203) = 54 msec.
Total seek time for the requests before the current position = 126 + 54 = 180 msec.
2. Calculate the total seek time for the requests after the current position:
Since the disk arm is moving from the largest to innermost cylinder, we need to calculate the seek time for the requests that are smaller than the current position.
- 145: The disk arm needs to move from cylinder 209 to 0 and then from 0 to 145, which requires 9 * (209 + 145) = 3342 msec.
- 122: The disk arm needs to move from cylinder 209 to 0 and then from 0 to 122, which requires 9 * (209 + 122) = 3105 msec.
Total seek time for the requests after the current position = 3342 + 3105 = 6447 msec.
3. Calculate the total seek time for the requests between the current position and the largest cylinder:
Since the disk arm is moving from the largest to innermost cylinder, we need to calculate the seek time for the requests that are between the current position and the largest cylinder.
- 75: The disk arm needs to move from cylinder 209 to 0 and then from 0 to 75, which requires 9 * (209 + 75) = 2700 msec.
- 106: The disk arm needs to move from cylinder 209 to 0 and then from 0 to 106, which requires 9 * (209 + 106) = 4149 msec.
Total seek time for the requests between the current position and the largest cylinder = 2700 + 4149 = 6849 msec.
4. Calculate the total seek time for the requests between the current position and the innermost cylinder:
Since the disk arm is moving from the largest to innermost cylinder, we need to calculate the seek time for the requests that are between the current position and the innermost cylinder.
- 40: The disk arm needs to move from cylinder 57 to 40, which
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Community Answer
Consider a disk that has 209 cylinders, starting from index 0. At some...
Algorithm - CSCAN
Requests - 5, 40, 75, 195, 145, 203, 106, 122
Current Cylinder - (208 - 57 + 1) = 151
Requests - 5, 40, 75, 195, 145, 203, 106, 122
Current Cylinder - (208 - 57 + 1) = 151
- Here, we start from the current cylinder, that is, 151 because as the question states, we are starting from the 57th cylinder from the largest cylinder. So, as per the chart, 57th cylinder from the right, that is, 151.
- The direction is from largest cylinder to innermost cylinder, that is, right to left.
- Now R/W head will move from 151 to 150, 150 to 149 and so on till it reaches 145. It reaches there and access the data. Total seek time till now can be calculated by: (151 - 145) * 1 = 6 msec. Similarly, R/W head will move from 145 to 122, 122 to 106 and so on till 0.
- Now when the R/W head reaches 0, it will jump to 208 and then continue moving in the same direction. Now, this jumping will take 9 msec. After that, it will move as is mentioned in (step - 3).
Calculation -
{[(151 - 145) + (145 - 122) + (122 - 106) + (106 - 75) + (75 - 40) + (40 - 5) + (5 - 0)] * 1} + {(208 - 0) * 9} + {[(208 - 203) + (203 - 195)] * 1} = 203
{[(151 - 145) + (145 - 122) + (122 - 106) + (106 - 75) + (75 - 40) + (40 - 5) + (5 - 0)] * 1} + {(208 - 0) * 9} + {[(208 - 203) + (203 - 195)] * 1} = 203
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Consider a disk that has 209 cylinders, starting from index 0. At some time, the disk arm is at the 57th cylinder from the end moving from largest to innermost cylinder. There is a queue of disk access requests for cylinders 5, 40, 75, 195, 145, 203, 106 and 122. The R/W head of the disk uses the Circular Scan algorithm to reach the disk and access the data. The disk arm requires 1 msec to move between adjacent cylinders and 9 msec to move between the largest and innermost cylinder. The total seek time is _______.Correct answer is '2036'. Can you explain this answer?
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Consider a disk that has 209 cylinders, starting from index 0. At some time, the disk arm is at the 57th cylinder from the end moving from largest to innermost cylinder. There is a queue of disk access requests for cylinders 5, 40, 75, 195, 145, 203, 106 and 122. The R/W head of the disk uses the Circular Scan algorithm to reach the disk and access the data. The disk arm requires 1 msec to move between adjacent cylinders and 9 msec to move between the largest and innermost cylinder. The total seek time is _______.Correct answer is '2036'. Can you explain this answer? for Computer Science Engineering (CSE) 2024 is part of Computer Science Engineering (CSE) preparation. The Question and answers have been prepared according to the Computer Science Engineering (CSE) exam syllabus. Information about Consider a disk that has 209 cylinders, starting from index 0. At some time, the disk arm is at the 57th cylinder from the end moving from largest to innermost cylinder. There is a queue of disk access requests for cylinders 5, 40, 75, 195, 145, 203, 106 and 122. The R/W head of the disk uses the Circular Scan algorithm to reach the disk and access the data. The disk arm requires 1 msec to move between adjacent cylinders and 9 msec to move between the largest and innermost cylinder. The total seek time is _______.Correct answer is '2036'. Can you explain this answer? covers all topics & solutions for Computer Science Engineering (CSE) 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Consider a disk that has 209 cylinders, starting from index 0. At some time, the disk arm is at the 57th cylinder from the end moving from largest to innermost cylinder. There is a queue of disk access requests for cylinders 5, 40, 75, 195, 145, 203, 106 and 122. The R/W head of the disk uses the Circular Scan algorithm to reach the disk and access the data. The disk arm requires 1 msec to move between adjacent cylinders and 9 msec to move between the largest and innermost cylinder. The total seek time is _______.Correct answer is '2036'. Can you explain this answer?.
Consider a disk that has 209 cylinders, starting from index 0. At some time, the disk arm is at the 57th cylinder from the end moving from largest to innermost cylinder. There is a queue of disk access requests for cylinders 5, 40, 75, 195, 145, 203, 106 and 122. The R/W head of the disk uses the Circular Scan algorithm to reach the disk and access the data. The disk arm requires 1 msec to move between adjacent cylinders and 9 msec to move between the largest and innermost cylinder. The total seek time is _______.Correct answer is '2036'. Can you explain this answer? for Computer Science Engineering (CSE) 2024 is part of Computer Science Engineering (CSE) preparation. The Question and answers have been prepared according to the Computer Science Engineering (CSE) exam syllabus. Information about Consider a disk that has 209 cylinders, starting from index 0. At some time, the disk arm is at the 57th cylinder from the end moving from largest to innermost cylinder. There is a queue of disk access requests for cylinders 5, 40, 75, 195, 145, 203, 106 and 122. The R/W head of the disk uses the Circular Scan algorithm to reach the disk and access the data. The disk arm requires 1 msec to move between adjacent cylinders and 9 msec to move between the largest and innermost cylinder. The total seek time is _______.Correct answer is '2036'. Can you explain this answer? covers all topics & solutions for Computer Science Engineering (CSE) 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Consider a disk that has 209 cylinders, starting from index 0. At some time, the disk arm is at the 57th cylinder from the end moving from largest to innermost cylinder. There is a queue of disk access requests for cylinders 5, 40, 75, 195, 145, 203, 106 and 122. The R/W head of the disk uses the Circular Scan algorithm to reach the disk and access the data. The disk arm requires 1 msec to move between adjacent cylinders and 9 msec to move between the largest and innermost cylinder. The total seek time is _______.Correct answer is '2036'. Can you explain this answer?.
Solutions for Consider a disk that has 209 cylinders, starting from index 0. At some time, the disk arm is at the 57th cylinder from the end moving from largest to innermost cylinder. There is a queue of disk access requests for cylinders 5, 40, 75, 195, 145, 203, 106 and 122. The R/W head of the disk uses the Circular Scan algorithm to reach the disk and access the data. The disk arm requires 1 msec to move between adjacent cylinders and 9 msec to move between the largest and innermost cylinder. The total seek time is _______.Correct answer is '2036'. Can you explain this answer? in English & in Hindi are available as part of our courses for Computer Science Engineering (CSE).
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Consider a disk that has 209 cylinders, starting from index 0. At some time, the disk arm is at the 57th cylinder from the end moving from largest to innermost cylinder. There is a queue of disk access requests for cylinders 5, 40, 75, 195, 145, 203, 106 and 122. The R/W head of the disk uses the Circular Scan algorithm to reach the disk and access the data. The disk arm requires 1 msec to move between adjacent cylinders and 9 msec to move between the largest and innermost cylinder. The total seek time is _______.Correct answer is '2036'. Can you explain this answer?, a detailed solution for Consider a disk that has 209 cylinders, starting from index 0. At some time, the disk arm is at the 57th cylinder from the end moving from largest to innermost cylinder. There is a queue of disk access requests for cylinders 5, 40, 75, 195, 145, 203, 106 and 122. The R/W head of the disk uses the Circular Scan algorithm to reach the disk and access the data. The disk arm requires 1 msec to move between adjacent cylinders and 9 msec to move between the largest and innermost cylinder. The total seek time is _______.Correct answer is '2036'. Can you explain this answer? has been provided alongside types of Consider a disk that has 209 cylinders, starting from index 0. At some time, the disk arm is at the 57th cylinder from the end moving from largest to innermost cylinder. There is a queue of disk access requests for cylinders 5, 40, 75, 195, 145, 203, 106 and 122. The R/W head of the disk uses the Circular Scan algorithm to reach the disk and access the data. The disk arm requires 1 msec to move between adjacent cylinders and 9 msec to move between the largest and innermost cylinder. The total seek time is _______.Correct answer is '2036'. Can you explain this answer? theory, EduRev gives you an
ample number of questions to practice Consider a disk that has 209 cylinders, starting from index 0. At some time, the disk arm is at the 57th cylinder from the end moving from largest to innermost cylinder. There is a queue of disk access requests for cylinders 5, 40, 75, 195, 145, 203, 106 and 122. The R/W head of the disk uses the Circular Scan algorithm to reach the disk and access the data. The disk arm requires 1 msec to move between adjacent cylinders and 9 msec to move between the largest and innermost cylinder. The total seek time is _______.Correct answer is '2036'. Can you explain this answer? tests, examples and also practice Computer Science Engineering (CSE) tests.
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