DiskSchedulingNov3

DiskSchedulingNov3 - Disk Scheduling Based on the slides...

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Disk Scheduling Based on the slides supporting the text 1
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User-Space I/O Software Layers of the I/O system and the main functions of each layer 2
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Disk Structure Disk drives are addressed as large 1-dimensional arrays of logical blocks , where the logical block is the smallest unit of transfer. The 1-dimensional array of logical blocks is mapped into the sectors of the disk sequentially. Sector 0 is the first sector of the first track on the outermost cylinder. Mapping proceeds in order through that track, then the rest of the tracks in that cylinder, and then through the rest of the cylinders from outermost to innermost. Lets understand track, sector and cylinder concept. 3
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Disk Scheduling The operating system is responsible for using hardware efficiently — for the disk drives, this means having a fast access time and disk bandwidth. Access time has two major components Seek time is the time for the disk are to move the heads to the cylinder containing the desired sector. Rotational latency is the additional time waiting for the disk to rotate the desired sector to the disk head. Minimize seek time
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DiskSchedulingNov3 - Disk Scheduling Based on the slides...

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