Question
In I/O scheduling, which of the following algorithms
minimizes seek time but may lead to starvation of requests at the ends of the disk?┬аSolution
The SCAN (Elevator Algorithm) moves the disk arm in one direction, servicing requests in that direction until it reaches the end of the disk, and then reverses direction. While this minimizes seek time by servicing requests in the current direction, it can cause starvation for requests located at the far ends of the disk, particularly if new requests continuously arrive closer to the middle of the disk. This behavior leads to longer wait times for the requests at the extreme ends of the disk. Why Other Options are Incorrect: A) FCFS: FCFS is a simple algorithm that services requests in the order they arrive, without consideration of seek time, and thus avoids starvation but does not minimize seek time. B) SSTF: SSTF selects the closest request to the current position, reducing seek time but also potentially causing starvation for requests far from the current position. D) C-SCAN: C-SCAN operates similarly to SCAN but only moves in one direction, avoiding starvation by providing equal treatment to all disk regions. E) LOOK Scheduling: LOOK is a variant of SCAN that stops moving when there are no more requests in the current direction, reducing the risk of starvation.
'рд╣рд┐рдиреНрджреАрддрд░' рдореЗрдВ рдкреНрд░рдпреБрдХреНрдд рдкреНрд░рддреНрдпрдп рд╣реИ
рд╡рд╛рдХреНрдпреЛрдВ рдХреЗ рд░рд┐рдХреНрдд рд╕реНрдерд╛рдиреЛрдВ рдХреА рдкреВрд░реНрддрд┐ рдХреЗ рд▓рд┐рдП рджрд┐рдП рдЧрдП рдЪрд╛рд░-рдЪрд╛рд░ рд╡я┐╜...
'рдЬреЛ рддреЛрд▓рд╛ рдорд╛рдкрд╛ рдЬрд╛ рд╕рдХреЗ' рдХреЗ рд▓рд┐рдП рдирд┐рдореНрдирд▓рд┐рдЦрд┐рдд рдореЗрдВ рд╕реЗ рдХреМрдирд╕рд╛ рд╢рдмреНрдж рд╣реЛ...
рдЕрдореЗрд░рд┐рдХрд╛ рдореЗрдВ рдПрдХ рдмрд╛рд░ ............ рд╣реБрдИ ред рджрд┐рдП рдЧрдП рдЙрдкрдпреБрдХреНрдд рд╢рдмреНрдж рд╕реЗ рд░рд┐рдХреНрдд я┐╜...
рдорд╛рдирдХ рд╣рд┐рдиреНрджреА рд╡рд░реНрддрдиреА рдХреА рджреГрд╖реНрдЯрд┐ рд╕реЗ рдирд┐рдореНрдирд▓рд┐рдЦрд┐рдд┬ардореЗрдВ┬ард╕реЗ рдХреМрди тАУ рд╕я┐╜...
рдЗрдирдореЗрдВ рд╕реЗ рдорд╛рдирд╡реАрдХрд░рдг рдЕрд▓рдВрдХрд╛рд░ рдХрд╛ рдХреМрди рд╕рд╛ рдЙрджрд╛рд╣рд░рдг рд╣реИ ?
'рдЖрдБрдЦ рдЦреБрд▓рдирд╛' рдореБрд╣рд╛рд╡рд░реЗ рдХрд╛ рд╕рд╣реА рдЕрд░реНрде рд╣реИрдГ
'рдЙрдЧреНрд░' рдХрд╛ рд╡рд┐рд▓реЛрдо рд╣реЛрдЧрд╛:
рдирд┐рдореНрдирд▓рд┐рдЦрд┐рдд рдореЗрдВ рд╕реЗ рдХреМрди рд╕рд╛ рд╡рд╛рдХреНрдп рд╢реБрджреНрдз рд╣реИ?
┬атАШрдореЛрд╣рди рд╕реЗ рдЪрд▓рд╛ рдирд╣реАрдВ рдЬрд╛рддрд╛ тАЩ рдЗрд╕ рд╡рд╛рдХреНрдп┬а рдХреЗ рд╡рд╛рдЪреНрдп рдХрд╛ рдирд╛рдо рд▓рд┐рдЦрд┐...