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Unit 7: Secondary Storage Structure
Notes
Required tracks: 98, 183, 37, 122, 14, 124, 14, 124, 65 and 67. Head starts at: 53
Figure 7.1: Total Tracks Covered: 53 to 98 = 45, 98 to 183 = 85, and so on = 640
Problems: Wild swing. Several close requests can be serviced together such as 37 and 14, 122
and 124 etc.
7.3.1 Shortest Seek Time First (SSTF)
Service all requests close to the current head position together, before moving the head far away
to service another request. This policy is similar to shortest job first.
Figure 7.2: Total Number of Tracks Covered: 236
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