I/O Buffering: I/O buffering is a technique used in computer systems to improve input and output (I/O) performance. It involves temporarily storing data in a buffer before it is read from or written to a device, such as a disk or network. This buffering reduces the frequency of accessing the device, improving overall system performance by allowing more efficient transfers of larger data blocks. Disk Scheduling: Disk scheduling is a process in operating systems that determines the order in which pending disk I/O requests are serviced. It aims to minimize disk head movement and optimize disk access time. Various scheduling algorithms, such as First-Come-First-Serve (FCFS), Shortest Seek Time First (SSTF), and SCAN, are employed to determine the order of request execution and improve disk performance. Disk Cache: A disk cache is a region of fast, volatile memory used to store frequently accessed data from a disk. It serves as a buffer between the central processing unit (CPU) and the slower disk storage. When the CPU needs to read or write data from or to the disk, it first checks the cache. If the data is present, it can be accessed much faster than if it had to be retrieved from the disk itself. Disk caching reduces disk access time, improves system performance, and enhances the overall responsiveness of the system. In summary, I/O buffering involves temporarily storing data in a buffer to improve I/O performance. Disk scheduling determines the order of disk I/O requests to optimize disk access time. Disk caching uses fast memory to store frequently accessed disk data, reducing disk access time and improving system performance. These techniques are employed in computer systems to enhance I/O operations and improve overall system efficiency.

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2. Our Team
Shahriar Ahsan
Taisiq
201002396
Sorove Jaman
Shanto
201002411
Emon Hossain
201002221
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3. Table of contents
I/O Buffering Types of I/O
Buffering
Disk Scheduling
Disk Scheduling
Algorithms
Disk Cache Disk Cache
Algorithms
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4. I/O Buffering
 Area of Main Memory
 Hold temporary Data Main Memory
Hold Data
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5. Double Buffer
Circular Buffer
Single Buffer
I/O
Buffer
Types of I/O Buffer
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6. Single Buffer
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7. Double Buffer
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8. Circular Buffer
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9. Disk Scheduling
• Scheduling I/O request arriving for the Disk
A general timing diagram of disk I/O transfer is shown here
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10. Seek Time
Transfer Time
Rotational Latency
Disk Time
Important
Terms
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11. Disk Scheduling Algorithms
FCFS Algorithm:
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12. Disk Scheduling Algorithms
SSTF Algorithm:
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13. Disk Scheduling Algorithms
SCAN Algorithm:
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14. Disk Cache
 Locality of Reference
 Replacement Strategy
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15. Page Replacement Algorithms
 LRU or Least Recently Used
 A stack of pointers references the cache
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16. Page Replacement Algorithms
 Frequency Based Replacement
 Blocks are logically organized in a stack, similar to LRU
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17. Thank You
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