Deck 19: Virtual Memory, Segmentation, and Disk Management

Question 1

The minimum number of page frames that must be allocated to a running process in a virtual memory environment is determined by

A)the instruction set architecture
B)page size
C)physical memory size
D)number of processes in memory

Answer 1

the instruction set architecture

Question 2

What is the reason for using the LFU page replacement algorithm?

A)an actively used page should have a large reference count
B)a less used page has more chances to be used again
C)it is extremely efficient and optimal
D)all of the mentioned

Answer 2

an actively used page should have a large reference count

Question 3

In segmentation, each address is specified by___________

A)a segment number & offset
B)an offset & value
C)a value & segment number
D)a key & value

Answer 3

a segment number & offset

Question 4

Each entry in a segment table has a

A)segment base
B)segment peak
C)segment value
D)none of the mentioned

Question 5

The segment limit contains the

A)starting logical address of the process
B)starting physical address of the segment in memory
C)segment length
D)none of the mentioned

Question 6

The offset 'd' of the logical address must be___________

A)greater than segment limit
B)between 0 and segment limit
C)between 0 and the segment number
D)greater than the segment number

Question 7

If the offset is legal___________

A)it is used as a physical memory address itself
B)it is subtracted from the segment base to produce the physical memory address
C)it is added to the segment base to produce the physical memory address
D)none of the mentioned

Question 8

When the entries in the segment tables of two different processes point to the same physical location___________

A)the segments are invalid
B)the processes get blocked
C)segments are shared
D)all of the mentioned

Question 9

The protection bit is 0/1 based on

A)write only
B)read only
C)read - write
D)none of the mentioned

Question 10

If there are 32 segments, each of size 1Kb, then the logical address should have

A)13 bits
B)14 bits
C)15 bits
D)16 bits

Question 11

Consider a computer with 8 Mbytes of main memory and a 128K cache. The cache block size is 4 K. It uses a direct mapping scheme for cache management. How many different main memory blocks can map onto a given physical cache block?

A)2048
B)256
C)64
D)8

Question 12

A multilevel page table is preferred in comparison to a single level page table for translating virtual address to physical address because___________

A)it reduces the memory access time to read or write a memory location
B)it helps to reduce the size of page table needed to implement the virtual address space of a process
C)it is required by the translation lookaside buffer
D)it helps to reduce the number of page faults in page replacement algorithms

Question 13

In___________information is recorded magnetically on platters.

A)magnetic disks
B)electrical disks
C)assemblies
D)cylinders

Question 14

The heads of the magnetic disk are attached to a___________that moves all the heads as a unit.

A)spindle
B)disk arm
C)track
D)none of the mentioned

Question 15

The set of tracks that are at one arm position make up a___________        

A)magnetic disks
B)electrical disks
C)assemblies
D)cylinders

Question 16

The time taken to move the disk arm to the desired cylinder is called the___________

A)positioning time
B)random access time
C)seek time
D)rotational latency

Question 17

The time taken for the desired sector to rotate to the disk head is called

A)positioning time
B)random access time
C)seek time
D)rotational latency

Question 18

When the head damages the magnetic surface, it is known as___________    

A)disk crash
B)head crash
C)magnetic damage
D)all of the mentioned

Question 19

What is the host controller?

A)controller built at the end of each disk
B)controller at the computer end of the bus
C)all of the mentioned
D)none of the mentioned

Question 20

___________  controller sends the command placed into it, via messages to the___________ controller.

A)host, host
B)disk, disk
C)host, disk
D)disk, host

Question 21

What is the disk bandwidth?

A)the total number of bytes transferred
B)total time between the first request for service and the completion on the last transfer
C)the total number of bytes transferred divided by the total time between the first request for service and the completion on the last transfer
D)none of the mentioned

Question 22

Whenever a process needs I/O to or from a disk it issues a___________    

A)system call to the cpu
B)system call to the operating system
C)a special procedure
D)all of the mentioned

Question 23

If a process needs I/O to or from a disk, and if the drive or controller is busy then

A)the request will be placed in the queue of pending requests for that drive
B)the request will not be processed and will be ignored completely
C)the request will be not be placed
D)none of the mentioned

Question 24

Magnetic tape drives can write data at a speed___________  disk drives.

A)much lesser than
B)comparable to
C)much faster than
D)none of the mentioned

Question 25

On media that use constant linear velocity (CLV), the___________  is uniform.

A)density of bits on the disk
B)density of bits per sector
C)the density of bits per track
D)none of the mentioned