The term fast wide SCSI-II denotes a SCSI bus that operates at a date rate 25
MB per second when it moves a packet of bytes between the host and device
Suppose that a fast wide SCSI-II disk drive spins at A PRM,has a sector size
of B bytes, and hold C sectors per track.
(a)Design a formula to estimate the sustained transfer rate of this drive in
MB (megabytes) per second.
A:
track size:B*C bytes.
rotational time:60/A sec.
transfer rate:[A*B*C/60]/10六次方
請問這樣對嗎?
(b)Suppose that the drive has a cylinders, b tracks per cylinder, a
head-switch time (from one platter to another)of c milliseconds,and an
adjacent-cylinder seek time of d milliseconds. Use this additional information
to derive a formula to give an accurate estimate of the sustained transfer
rata for a 100 cylinder huge transfer.
A:
track transfer time: 60/A sec.
cylinder transfer time: (60*b/A)+c*(b-1) sec
100 cylinder transfer time: 100*[(60*b/A)+c*(b-1)]+99*d sec.
請問這樣對嗎?
(c)Suppose that the average seek time for the drive is 8 milliseconds.Estimate
the I/0s per second and the effective transfer rate for a random-access
workload reads individual sectors scattered across the disk.
這題不會，有人會解嗎，謝謝。
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