代做CS365: Operating Systems Assignment 3: Hard disk, BSF, SDD, etc代做Python编程

CS365: Operating Systems

Assignment 3: Hard disk, BSF, SDD, etc

1. What’s the purpose of a hard drive? (       )

A.   Store Long Term Memory

B.   Store Fat Term Memory

C.   Store Short Term Memory

D.  Store Memory

2. what is the recommended hard drive? (      )

A.   PATA

B.   SATA

C.   SSD

D.   HDD

3. Which was the biggest hard drive? (        )

A.   HDD

B.   IBM 1311 Disc Storage Drive

C.   SSD

D.   IBM (RAMAC)

4. Moore's law states that transistor density doubles every

A.   1 year   B.   2 years C.   3 years D.  4 years

5. This type of drive is superior in random reading performance. SSD or HDD?

A.   SSD.                B.  HDD                           C.  Neither                        D.  Bot

6. Management of metadata information is done by

A.   File-organization module

B.   Logical file system

C.   Basic file system

D.  Application programs

7. A file control block contains information about

A.   File ownership

B.   File permissions

C.   Location of file contents

D.  All of the mentioned

8. If the block of the free-space list is free, then bit will

A. 1

B. 0

C.  Any of 0 or 1

D.   None of the mentioned

9. [10    points] One of the innovations of the BSD FFS is that it tries to allocate large files in long contiguous chunks. Assuming that a disk transfers at a peak rate of 100

MByte/s, and that a combined seek and rotation take, on average, a total of 20 milliseconds. What is the minimum size of each contiguous run of a large file, in order to achieve 75% of peak transfer rate for large files when they are accessed sequentially?

10. [20    points] Consider a FAT-based (File Allocation Table) file system. Entries in the table are16 bits wide. A user wants to install a disk with 131072 512-byte sectors.

a)    What is a potential problem?

b)    Describe a solution to this problem and explain the trade-offs involved.

11. [20 points] Briefly describe the steps taken to read a block of data from the disk to the

memory using DMA-controlled I/O.

12.  [10   points] Why is it impossible to have a hard link to a file in a different file system?