OS Input Output Systems

Question 51

Match the following w.r.t. Input/Output management

• (1)

• (2)

• (3)

• (4)

Question 52

Consider a disk pack with 16 surfaces, 128 tracks per surface and 256 sectors per track. 512 bytes of data are stored in a bit serial manner in a sector. The capacity of the disk pack and the number of bits required to specify a particular sector in the disk are respectively:

• 256 Mbyte, 19 bits
• 256 Mbyte, 21 bits
• 512 Mbyte, 20 bits
• 64 GB, 28 bits

Question 53

There are 200 tracks on a disc platter and the pending requests have come in the order - 36, 69, 167, 76, 42, 51, 126, 12 and 199. Assume the arm is located at the 100 track and moving towards track 199. If sequence of disc access is 126, 167, 199, 12, 36, 42, 51, 69 and 76 then which disc access scheduling policy is used?

• Elevator
• Shortest seek-time first
• C-SCAN
• First Come First Served

Question 54

Consider a file currently consisting of 50 blocks. Assume that the file control block and the index block is already in memory. If a block is added at the end (and the block information to be added is stored in memory), then how many disk I/O operations are required for indexed (single-level) allocation strategy?

• 1
• 101
• 27
• 0

Question 55

Consider a system where each file is associated with a 16 bit number. For each file, each user should have the read and write capability. How much memory is needed to store each user\'s access data?

• 16 KB
• 32 KB
• 64 KB
• 128 KB

Question 56

In case of a DVD, the speed of data transfer is mentioned in multiples of?

• 150 KB/s
• 1.38 MB/s
• 300 KB/s
• 2.40 MB/s

Question 57

Suppose we have variable logical records of lengths of 5 bytes, 10 bytes, and 25 bytes while the physical block size in disk is 15 bytes. What is the maximum and minimum fragmentation seen in bytes?

• 25 and 5
• 15 and 5
• 15 and 0
• 10 and 5

Question 58

A fast wide SCSI-II disk drive spins at 7200 RPM, has a sector size of 512 bytes, and holds 160 sectors per track. Estimate the sustained transfer rate of this drive

• 576000 Kilobytes / sec
• 9600 Kilobytes / sec
• 4800 Kilobytes / sec
• 19200 Kilobytes / sec

Question 59

The primary purpose of an operating system is

• To make most efficient use of the computer hardware
• To allow people to use the computer
• To keep systems programmers employed
• To make computers easier to use

Question 60

Using a larger block size in a fixed block size file system leads to

• better disk throughput but poorer disk space utilization
• better disk throughput and better disk space utilization
• poorer disk throughput but better disk space utilization
• poorer disk throughput and poorer disk space utilization