Concern a disk with a sector size of 512 bytes, 2000 tracks per surface, 50…
2020
Concern a disk with a sector size of 512 bytes, 2000 tracks per surface, 50 sectors per track, five double-sided platters, and average seek time of 10 milliseconds.
Given below are two statements:
Statement 𝐼: The disk has a total number of 2000 cylinders.
Statement 𝐼𝐼: 51200 bytes is not a valid block size for the disk.
In the light of the above statements, choose the correct answer from the options given below:
- A.
Both Statement 𝐼 and Statement 𝐼𝐼 are true
- B.
Both Statement 𝐼 and Statement 𝐼𝐼 are false
- C.
Statement 𝐼 is correct but Statement 𝐼𝐼 is false
- D.
Statement 𝐼 is incorrect but Statement 𝐼𝐼 is true
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Correct answer: A
Key facts:
Number of cylinders = number of tracks per surface = 2000.
Number of surfaces: five double-sided platters → 5 × 2 = 10 surfaces. Total sectors = 2000 tracks/surface × 50 sectors/track × 10 surfaces = 1,000,000 sectors.
Sector size = 512 bytes. Size per track = 50 sectors × 512 bytes = 25,600 bytes.
Block size to check: 51,200 bytes = 512 bytes × 100 (i.e., 100 sectors).
Typical requirement for filesystem block sizes: they are multiples of the sector size and usually a power-of-two multiple (common block sizes in bytes include 512, 1024, 2048, 4096, 8192, 16384, 32768, 65536).
Because 51,200 = 512 × 100 and 100 is not a power of two, 51,200 bytes is not a standard valid block size for typical filesystems despite being a multiple of the sector size.
Conclusion: Both Statement I and Statement II are true.
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