ANHNH OSG202 ĐỀ 1 CH

ANHNH OSG202
ĐỀ 1 CH
1)_____ is a small computer that fits in a shirt pocket and performs a small number of
functions, such as an electronic address book and memo pad *
A. Personal Digital Assistant B. Personal Device
C. Personal Computer D. Personal Operating System
2)Each process is associated with _________ *
A. address space, set of program’s source files, pointer, etc
B. address memory, linker, compiler, etc
C. all of the others
D. address space, set of resources, registers, etc
3)How many ways are Thread implemented? *
A.1 B.2 C.3 D.4
4)The Joliet Extensions provide ________ *
A. Directory nesting deeper than 8 levels B. Directory names with extensions
C. All of the others D. Long file name is supported Unicode character
5)A disk queue with requests for I/O blocks on cylinders in orders: 10, 22, 20, 2, 40, 6, 38.
Assume that the disk head is initially at cylinder 9. How many cylinders do Total head
movement using SSF algorithms? *
A. None of the others B. 69 C. 47 D. 45
6)What’s different between preemptable and non-preemptable resources? *
A. All of the others
B. Effecting on process or system can occur when those resources are taken way
C. None of the others
D. Preemptable resources can be separated
7)Which of the following statement is a disadvantage of separating I/O and memory space? *
A. Caching a device control register would be disastrous
B. The set of all the I/O ports is protected so that the ordinary users must use 2 instructions
C. All of the others
D. Since the control registers of devices are mapped into the memory space, device drivers
can be written without using Assembly language
8)Which of the following synchronization mechanisms does rely on busy waiting? *
A. All of the others B. Peterson's algorithm
C. Monitors D. Message passing

9)Rearrange the layers in I/O software starting at the bottom: 1. User-level I/O software; 2.
Device drivers; 3. Interrupt handlers; 4. Hardware; 5. Device-independent OS software. *
A. 15234 B. 12345 C. 54321 D. 43251
10)Which deadlock condition does order resources numerically attack? *
A. Hold and wait B. Circular wait
C. Mutual exclusion D. None of the others
11)How many ways are to used to keep track of free block in disk space management? *
A. A bitmap method B. A linked list method
C. All of the others D. A indexed method
12)Which method is used to prevent the communication deadlock? *
A. Acknowledge signal B. Handling alarm
C. Timeouts D. All of the others
13)An interrupt that does not meet these requirements is called a(n) ______ *
A. Required interrupt B. Precise interrupt
C. Disappointed interrupt D. Imprecise interrupt
14)If there are 64 pages and the page size is 4096 words, what is the length of logical
address? *
A.12 bits B. 8 bits C. 16 bits D. 18 bits
15)Suppose a virtual address space of 2^24 words and the page size is 2^12 words. If the
virtual address is 1234567 in Hexadecimal, what would be the page number in Hexadecimal? *
A. 123 B. 1234 C. 246 D. 2468
16)What is a “tripping” in RAID? *
A. Get undressed B. All of the others
C. Take away possessions from someone D. Distributing data over multiple drives
17)Which statement about the Producer-Consumer Problem to get trouble is true? *
A. The wake up signal is lost
B. All of the others
C. The consumer and producer will sleep forever
D. Access to count variable is unconstrained
18)Which operating system structure is communication between requesting process and
responding process by message passing? *
A. Monolithic Systems B. All of the others
C. Client – Server Model D. MS – DOS
19)A system has five processes and three allocated resources. The current allocation and
request needs are as following figure. What do the processes progress in sequence?

A. ABCDE B. ADCEB C. ADECB D. ACDEB
20)Where is all the information about each process stored in operating systems? *
A. Process table B. Program table
C. Page table D. Virtual table
21)Which problem is described two following statements? 1. No reader will be kept waiting
unless a writer has already obtained permission to use the shared object. Or, readers have
higher priorities; 2. Once a writer is ready, the writer performs its write as soon as possible *
A. Readers-Writers B. Bankers
C. All of the others D. Producer-Consumer
22)Which of the following is a synchronization primitive that is implemented by hardware? *
A. Lock variables B. The TSL instructions
C. Peterson's Solution D. Strict Alternation
23)Five batch jobs A through E, arrive at a computer center at almost the same time. They
have estimated running times of 8, 6, 2, 10, and 4 minutes. Their (externally determined)
priorities are 3, 5, 2, 1, and 4, respectively, with 5 being the highest priority. Determine the
mean process 'average waiting time for priority scheduling'. Ignore process switching
overhead. *
A. 54 minutes B. 12,8 minutes
C. 10,8 minutes D.16,8 minutes
24)Which strategy is a simplest design for speeding up Paging? *
A. Page table is loaded into disk
B. Page table is loaded into TLB
C. Page table is loaded into registers
D. Page table is loaded into main memory
25)Which solution is used to solve the “missing block” problem in file system consistency? *
A. The file system checker allocate the free block, then copy the duplicate block in used to
there

B. None of the others
C. The file system checker adds the missing blocks to the free list
D. The file system checker rebuilds the free list
26)Which are file types? *
A. Block special files B. Regular files
C. Character special files D. All of the others
27)A(n) _________ is provided to make system calls from some programming languages *
A. None of the others B. pointer
C. operator D. procedure library
28)In a directed graphs model, a possible of deadlock can occur: *
A. None of the others
B. If graph contains a cycle and only one instance process per resource type
C. If graph contains a cycle and several instances per resource type
D. If graph contains no cycle
29)Operating system abstraction supports the ability to have ______ operation even when there
is only one CPU available *
A. None of the others B. parallel C. multiple D. pseudoparallelism
30)Which solutions are used to solve the shared libraries? *
A. Relocation on the fly and position-independent code
C. Static reallocation and position-independent code
D. Copy on write and position-independent code
31)Why is Shortest Job First scheduling algorithm optimal? *
A. Each process is assigned a time interval during which it is allowed to run
C. Minimize average waiting time of each process
D. Each process is assigned a priority that the process with the highest priority is allowed to
run
32) Five batch jobs A through E, arrive at a computer center at almost the same time. They
have estimated running times of 8, 6, 2, 10, and 4 minutes and arrival times at 0, 4, 6, 10 and
12. Determine the mean process 'average turnaround time' for FCFS (First-Come First Served)
scheduling. Ignore process switching overhead. *
A. 6,4 minutes B. 62 minutes C. 12,4 minutes D. 32 minute
33)A system has five processes and three allocated resources. The current allocation and
maximum needs are as following figure. What is the smallest value of x for which this is a safe
state? *

A. 3 B. 2 C. 1 D. 0
34)To specify an address in this segmented memory, the _____ form is used *
A. <segment-number, offset> B.<virtual address, offset>
C.<process, offset D. <physical address, offset>
35) What is the “sequential processes” concept? *
A. There are both many CPU and many PC
C. All process is executed in concurrency
D. No concurrency inside a process; everything happens sequentially
36)Consider an i-node which contains 10 direct addresses of 4 bytes each and all disk blocks
are 1 KB. Also consider that the i-node contains an additional “single and double indirect
address” that is used for containing more disk block addresses. What is the largest possible
file? *
A. 10 KB B. 65536 KB C. 65802 KB D. 266 KB
37)The number on the address lines is used as an index into a table to fetch a new program
counter. What is the table’s name? *
A. Interrupt table B. Address table
C. Interrupt vector D. Address lines table
38)Which method is used to implement files with file’s size larger than 2 GB in UNIX V7? *
A. FAT 16
B. FAT 32
C. i-node with single indirect block
D. i-node with triple indirect block
39.) Which method is used to implement files to keep each file as a linked list of disk blocks? *
A. Contiguous Allocation B. Linked List Allocation
C. i-node D. File Allocation Table
40) In “No Memory Abstraction”, the static relocation technique is ____ *

A. After the program is loaded at address n, the constant n is stored at a particular register.
C. When the program is compiled, the address of program is added with the constant value
where the program will be loaded
D. When the program is loaded at address n, the constant n was added to every program
address
41) Which mechanism is described as “the device controller sneaks in and steals an occasional
bus cycle from the CPU once in a while, delaying it slightly”? *
A. Interrupt stealing B. All of the others
C. Cycle sneaking D. Cycle stealing
42) Which concept is described as “disk sectors are just numbered consecutively starting at 0,
without regard to the disk geometry”? *
A. Logical block addressing B. Physical block addressing
C. Virtual block addressing D. None of the others
43) What is one directory containing all files called in the simplest form of directory system? *
A. Parent directory B. Root directory
C. Volume D. User directory
44) A disk queue with requests for I/O blocks on cylinders in orders: 10, 22, 20, 2, 40, 6, 38.
Assume that the disk head is initially at cylinder 38. Which the ordering cylinder in progress
do using a slight modification of elevator algorithms? *
A. 38 38 40 22 20 10 6 2
B. 38 38 40 2 6 10 20 22
C. 38 38 22 20 10 6 2 40
D. 38 40 2 6 10 20 22 38
45) Which keyword is appropriate described in the following statement: “While memory sizes
are increasing rapidly, software sizes are increasing much faster”? *
A. swapping B. bloatware C. overlays D. paging
46) The File System Performance is implemented by _____ *
A. Buffer cache B. Defragmenting Disks D. Block Read Ahead E. All of the others
47) One of way to prevent a deadlock is ________ *
A. Kills one of the processes B. Rollback
C. Spool everything D. Locks one of the processes
48) What is the correct approach with requesting the dedicated devices to solve deadlock using
Ostrich algorithm? *
A. The device driver stops the current jobs and releases the devices
B. The device driver kills those requesting processes
C. The device driver decides blocking and returning an error code
D. All of the others

49) Assume that the Page Table below is in effect. The number of lines per page is 400. The
actual memory location for line 1634 is ____. *
A. 3 B. None of the others C. 4434 D. 1634
50) A memory free in 3 frames. How many times do the page fault occur? Assume that the
running as the following page 7, 0 , 1, 2 , 0, 3, 0 , 4, 2 , 3 , 0 , 3 , 2 , 1, 2, 0, 1, 0 , 7 using
LRU. *
A. 7 times B. 6 times C. 12 times D. 13 times
51)What is the advantage of the exokernel scheme? *
A. Try to use somebody else’s resource
C. Maintain tables to remap disk address
D. Save a layer of mapping
52) Assume jobs A-D arrive in quick succession in the READY queue. Using round robin
scheduling (quantum=4), the average turnaround time for each job is ____. *
A. 5 B. 73 C. 18.25 D. 20
53) What’s different between asynchronous and synchronous transfer in principles of I/O
software? *
C. The CPU starts the transfer and goes off to do something else until the data are available in
the buffer
D. The CPU starts the transfer and goes off to do something else until the interrupt arrives
54) A memory free in 3 frames. Which values do the page frame contain after the 4th page is
accessed? Assume that the running as the following page 7, 0 , 1, 2 , 0, 3, 0 , 4, 2 , 3 , 0 , 3 , 2 ,
1, 2, 0, 1, 0 , 7 using LRU. *

A. 7, 0, 1 B. 4, 0, 3 C. 1, 0, 7 D. 3, 0, 4
55) Assume that process A-D make up the set of runnable processes on memory asB1 B2 B3
A1 A2 A5 A7 D3 D4 D6 C1 C6 C5. Suppose D gets a page fault. Which page is replaced using
the local policy? Assume that the replaced page is always a last page. *
A. B3 B. C5 C. D6 D. None of the others
56) Which mechanism is implemented by writing to the log file in file system management and
optimization? *
A. Log-Structured File Systems B. None of the others
C. Virtual File Systems D. Journaling File Systems
57) Which of these statements about the Inverted Page Table are true? *
A. An entry contains the pair (segment, virtual page) mapped into the corresponding page
frame
B. An entry contains the pair (process, virtual page) mapped into the corresponding page
frame
C. An entry contains the pair (segment, offset) mapped into the corresponding page frame
D. An entry contains the pair (process, offset) mapped into the corresponding page frame
58) Consider a swapping system in which the memory consists of the following hole sizes:
10K, 4K, 20K, 15K, 9K. Assume worst fit algorithm is used. Which holes are taken for
successive segment requests of 8K, 12K, 10K? *
A. 9K, 15K, 10K B. 20K, 15K, 10K
C. 10K, 15K, 20K D. 10K, 20K, 15K
59) Which thread does the arrival of a message cause the system to create a new thread to
handle the message? *
A. Upcall B. Pop-up C. Distributed D. Activator
60) The live lock is resolved by ________ *
A. All of the others
B. Killing the process itself.
C. Restricting all users to one process, one open file, and one everything
D. None of the others
ĐỀ 2 CH
61) Which mechanism is described as “the device controller sneaks in and steals an occasional
bus cycle from the CPU once in a while, delaying it slightly”? *
A. Cycle stealing B. Interrupt stealing
C. All of the others D. Cycle sneaking

62) A ____ is a portion of a process that can run independently *
A. subprocess B. thread C. program D. miniprocess
63) Dijkstra’s Banker’s Algorithm require the system to maintain the resource information for
each process, including (choose 1 answer only): *
A. A count of the system’s total resources
B. The number of resources currently acquired by the process
C. The maximum resources that can be requested by the process and The number of resources
currently acquired by the process
D. The maximum resources that can be requested by the process
64) The special files are (choose 1 answer only): *
A. block special file
B. none of the other choices
C. character special file
D. character special files and block special files
65) Which of the following is an advantage of Memory-mapped I/O? *
A. None of the other choices
B. Since there is only one address space, all I/O devices must examine all memory references
. to see which ones to response to
C. Since the control registers of devices are mapped into the memory space, device drivers
D. Using memory mapped I/O, caching a device control register is not acceptable
66) Which of the following statements is incorrect about Translation Look-aside Buffer
(TLB)? *
B. The use of TLB eliminates the need for keeping a page table in memory
C. TLB only maintains a subset of the entries stored in the full memory-based page table
D. When there is a TLB miss the system needs to access the page table
67) Linux and __________ are often used as operating systems on supercomputers,
mainframes, and servers. *
A. Windows B. UNIX
C. Mac OS D. None of the other choices
68) Which of the following is not correct about the reliability of different RAID levels? *
A. All RAID levels can survive one disk crash
B. In RAID level 2, a single bit error in a word can be detected AND corrected
C. In RAID levels 3, 4, 5 a single bit error in a word can be detected
D. There is no reliability support in RAID level 0
69) Typical approaches to handle deadlocks do not include *
A. Detection B. Deterrence C. Prevention D. Avoidance

70) Which of the following process state transitions is illegal? *
A. blocked -> running B. ready -> running
C. blocked -> ready D. running -> ready
71) Which of the following is not correct about hard links and symbolic links? *
A. Symbolic links can point to files in the network
B. Hard links can point to files on other machines
C. Hard links do not require extra disk space
D. Symbolic links need space to store the name of the file pointed to
72) What are the allocation methods of disk blocks for files: *
A. Linked allocation B. Contiguous allocation
C. All of the other choices D. Indexed allocation
73) The I/O technique where the processor busily waits for an I/O operation to complete is
called: *
A. None of the other choices B. Programmed I/O
C. Direct Memory Access (DMA D. Interrupt-driven I/O
74) A page fault means that we referenced a page *
A. that was outside the memory boundaries
B. that was not in main memory
C. that was not in secondary storage
D. with an incorrect I/O request
75) Personal desktop computers use a __________ operating system. *
A. real-time B. multiuser C. single-user, multitask D. single-user, single-task
76) Which of the following conditions of semaphore variable “s” implies a busy critical
region? *
A. s < 0 B. s = 0 C. None of the other choices D. s > 0
77) Which of the following synchronization mechanisms does not rely on busy-waiting? *
A. Lock variables B. Semaphores C. Peterson’s algorithm. D. Strict alternation
78)Which strategy is used in the Banker’s algorithm for dealing with deadlocks? *
A. Deadlock prevention B. Deadlock detection
C. Deadlock avoidance D. Deadlock ignorance
79) What is not correct about contiguous allocation of files? *
A. It is widely used on CD-ROMs
B. It does not cause disk fragmentation
C. It leads to excellent read performance

D. It is simple to implement
mean process average turnaround time for priority scheduling. Ignore process switching
overhead . *
A. 12,8 minutes B. 16,8 minutes C. 54 minutes D. 10,8 minutes
81) Which of the following statements about semaphores is true? *
A. A semaphore implementation should guarantee that processes do not suffer indefinite
postponement
B.P and V (Down and Up) operations should be indivisible operations
C. If several processes attempt a P(S) operation simultaneously, only one process should be
allowed to proceed
D. All of the other choices
82) Which of the following statements is incorrect about I/O using DMA? *
A. DMA helps free up the CPU during the I/O to do other work
B. None of the other choices
C. In essence, DMA is programmed I/O, except the fact that DMA, instead of the CPU, does
all the work
D. DMA helps reduce the number of interrupts
83) Which of the following statements about segmentation is false? *
A. Sharing of procedures between different users can be facilitated
B. The total address space can be more than the size of physical memory
C. None of the other choices
D. There are several linear address spaces
84) A computer has four page frames. The time of loading, time of last access, and the R and
M bits for each page are as shown below (the times are in clock ticks). Which page will
Second Chance replace? *
A. 0 B. 2 C. 3 D. 1

85.In general, which is the best technique for I/O Data transfer? *
A. Direct Memory Access
B. Programmed I/O
C. Interrupt-Driven I/O
D. None of the other choices
86) All deadlocks involve conflicting needs for resources by *
A. Two or more processes
B. One or more processes
C. Three or more processes
87)Which of the following is a hardware solution to the critical region problem? *
A.TSL B. Shared memory
C. None of the other choices D.Semaphore
88) A directory in UNIX/Linux consists of the following *
A. file name, file size, location of the file on disk
B. i-node number and file name
D. file name, file size, location of the file on disk, date created, owner ID
89)A table in main memory storing linked list allocation of disk blocks is called: *
A. File allocation table B. File list table
C. Disk allocation table D.. Linked list table
90)With paging, when is the internal fragmentation possible? *
A. The virtual memory assigned to the program is less than the physical memory assigned to
it
B. The last page of the job is less than the maximum page size
C. Page does not fit the frame
D. Such thing cannot happen
91) Which of the following is not a well-known technique for organizing the physical storage
blocks for a file? *
A. Linked list block allocation B. Contiguous block allocation
C. Indexed block allocation D. Sparse block allocation
Assume that the disk head is initially at cylinder 9. How many cylinder do total head
A. None of the others B. 43 C. 67 D.45
93) In which of the following environments preemption is essential? *
A. Interactive

B. Real time
C. Batch
1/1
A. 4000 B. 33 C. 4033 D.1
95)Consider the following state of a system with four processes P1, P2, P3 and P4 and five
types of resources RS1, RS2, RS3, RS4 and RS5 as figure below. Deadlocked processes are
___ *
A. P1, P4
B. P1, P2
C. P2, P3
D. P1, P3
96)Which of the following is specified to indicate the directory where the file is located? *
A. Root directory B. Extension C. Sub-directory D. Path name
97) Which deadlock condition does order resources numerically attack? *
A. Mutual exclusion B. None of the other choices
C. No preemption D. Hold and wait
98) Which of the following actions generates an external interrupt? *
A. A system call instruction is executed.
B. An input/output operation is completed.
C. A page that does not exist in the main memory is accessed by the virtual storage
management.

D. Division by zero occurs.
99) The simplest way to break a deadlock is to *
A. kills one of the processes
B. locks one of the processes
C. preempt a resource
D. rollback
100)Assume jobs A-D arrive in quick succession in the READY queue. Using round robin
A. 5 B. 18.25 C. 73 D. 20
101) Which part of a disk is used to boot the computer? *
A. MBR B. Boot block C. Root block D. Super block
102) Which of the following statements is incorrect about user mode and kernel mode? *
A. In kernel mode, the OS can execute every instruction in the instruction set
B. In user mode, user program can execute only a subset of instructions
D.Having two modes of operation helps prevent user programs from accessing critical
instructions
103) Consider a swapping system in which the memory consists of the following hole sizes: 10
K, 4 K, 20 K, 15 K, 9 K. Assume best fit algorithm is used. Which holes are taken for
successive segment requests of 8 K, 12 K, 10 K? *
A. 10 K, 20 K, 15 K B. 9 K, 15 K, 10 K
C. None of the other choices D. 20 K, 15 K, 4 K
104) Which of the following is a preemptive scheduling algorithm *
A. Shortest Job First B. None of the other choices
C. FCFS D. Round Robin
105) Which of the following systems is used in time-critical environments where data must be
processed within a strict time limit? *
A. Interactive B. Hybrid C. Embedded D. Real-time
106) ____ is the partitioning of a single server, each of which can support a different
operating *
A. Multithreading B. Multiprocessing C. Virtualization D. Shared processing
107) The File Manager writes the volume name and other descriptive information on an easy-
to-access place on each unit: ____ of the CD or DVD *

A. stored at the beginning of the volume
B. the innermost part
C. the outermost part
D. immediately following the master file directory
108) Which statement about disabling interrupts to resolve race conditions is wrong? *
A. User-mode programs are the best place to invoke disableInterrupt()
B. In theory, a program can disable interrupts when it enters a critical section, and re-enable
interrupts when finished with a critical section, to eliminate race conditions
C. Disabling/enabling interrupts may negatively affect the I/O system
D. Programs with infinite loops in their critical sections are a significant problem with the
interrupt-based approach
109) Working set model is used for: *
A. Finding the average number of frames a job will need to run smoothly
B. Finding the minimum number of frames necessary for a job so that jobs can be run without
“thrashing”
C. Determining whether page replacement is needed
K, 4 K, 20 K, 15 K, 9 K. Assume worst fit algorithm is used. Which holes are taken for
B. 10 K, 20 K, 15 K
C. 9 K, 15 K, 10 K
D. 20 K, 15 K, left over of 20 K
111) Which is a wrong statement about the quantum used in Round Robin algorithm? *
A. A reasonable value of quantum is around 20-50 ms
C. If the quantum is very small, the CPU efficiency is reduced
D. If the quantum is very large, RR is essentially FCFS
112) Which of the following statements about interrupts and trap instructions is incorrect? *
A. An interrupt is a hardware-generated change of control flow within the system
B. A trap instruction is a software-generated interrupt
D. An interrupt handler deals with the cause of the interrupt
113) Which of the following statements is incorrect about Memory-mapped I/O and
Programmed I/O? *
B. Programmed I/O may use memory-mapped I/O to fulfill the I/O tasks
C. Memory-mapped I/O is a way to control the device
D. Programmed I/O is a way to actually carry out the I/O operations

114) What is the weakness of the Banker’s algorithm? *
A. Enabling the number of resources to fluctuate
B. Requiring that processes state their maximum needs in advance
C. Allowing the population of processes to vary over time
D. Enabling processes to hold their resources indefinitely
115) Which of the following statements about the CPU’s handling interrupts is incorrect? *
A. The processor ceases to execute the current sequence of instructions
B. The hardware saves the old PC location
C. The CPU branches to a new instruction sequence
116) In a directed graphs model, a possible of deadlock can occur: *
B. If graph contains no cycle
C. If graph contains a cycle and only one instance per resource type
D. If graph contains a cycle and several instances per resource type
117) What is interrupt vector? *
B. A signal an I/O device sends to CPU
C. A signal CPU sends to I/O device
D. Part of memory which contains the addresses of interrupt handlers
118) Information that must be saved prior to the processor transferring control to the interrupt
handler routine includes: *
A. PSW and Contents of processor registers
B. PSW and PC
D. PSW
(TLB)? *
A.A TLB miss implies a disk operation will follow
B. A TLB is sometimes known as an associative memory
C. Each entry of a TLB contains the information about one page, including the virtual page
number and the corresponding page frame
120) Each of the following characteristics applies to deadlock avoidance except *
B. Inherently conservative strategy
C. Relying on ability to predict effect of satisfying allocation requests

D. Widely used in modern operating systems
ĐỀ 4 CH
121)Assume jobs A-D arrive in quick succession in the READY queue. Using round robin
scheduling (quantum=4), the turnaround time for job A is ____. *
A.22 B. 20 C. 7 D. 24
122) Which does the power of CPU decrease to if it run at half speed? *
A. None of the other choices B. 1/8 C. ¼ D. 1/2
123) A(n) _________ is provided to make system calls from some programming languages *
A. procedure library B. operator
C. none of the other choices D. pointer
124) What is correct about trap instructions and interrupts? *
A. A trap instruction is caused by a user program to invoke functions in the OS kernel
B. An interrupt is caused by an external event
C. Trap instruction switches the execution mode of a CPU from the user mode to the kernel mode.
125) Which of the following is not a task of I/O management of OS? *
A. Mapping files onto secondary storage
B. Manage main memory for the devices using caching, buffering, and spooling
C. Maintain and provide a general device-driver interfaces
D. Drivers for specific hardware devices
126) Which method is used to implement files to keep each file as a linked list of disk
blocks? *
A. Linked List Allocation B. Contiguous Allocation
C. i-node D. File Allocation Table
127) Assuming that it takes 10 nsec to copy a byte, how much time does it take to completely
rewrite the screen of a 1200 x 800 pixels graphics with 24- bit color? *
A. 28.8 msec B. 288 micro-sec
C. 288 msec D. 28.8 micro-sec
128) Which is not a DVD Improvement on CDs to increase the capacity? *
A. A kind laser (red, blue) B. Diameter of disc
C. Smaller pits D. A tighter spiral
129) A simplest way to break a deadlock is to *
A. rollback B. preempt a resource
C. kills one of the processes D. locks one of the processes
130) Which of the following is an Operating System component? *
A. Space Management B. Speed Management
C. Time Management D. Process Management

B. Inherently conservative strategy
C. Widely used in modern operating systems
D. Relying on ability to predict effect of satisfying resource allocation requests
132) A computer has four page-frames. The time of loading, time of last access, and the R and
M bits for each page are as shown below (the times are in clock ticks). Which page will FIFO
replace? *
A. 1
B. 2
C. 0
D. 3
133) How much cylinder skew is needed for a 7200- RPM (rotate per minute) disk with the
track-to-track seek time of 1 msec? The disk has 200 sectors of 512 bytes on each track. *
A. 12 sectors B. 36 sectors C. 24 sectors D. 18 sectors
134) Of the three components of access time in a disk, ____ is the longest. *
A. Delay time B. Transfer time C. Search time D. Seek time
135) An algorithm designed to detect starvation by tracking how long each job has been
waiting for resources is the same concept as ____. *
A. Aging B. Preemption C. Round robin D. Deadlock
136) Which FAT type is used, if the maximum partition size is 256 MB and the block size is
4KB? *
A. FAT-32 B.FAT-12 C. None of the other choices D. FAT-16
137) To specify an address in this segmented memory, the _____ form is used *
A. <process, offset> B. <physical address, offset>
C. <segment-number, offset> D. <virtual address, offset>
138)Which of the following statements is not correct about Graphic adapter? *
A. Supports different method of coding pixel color
B. Contains a special memory called video RAM
D. Supports some number of screen sizes (resolution)
139) Strategy used for dumping a disk to tapes is: *

A. None of the other choices B. Both physical dump and logical dump
C. Logical dump D. Physical dump
140) Assuming that it takes 10 nsec to copy a byte, how much time, does it take to completely
rewrite the screen of a 150 characters x 20 line text mode memory-mapped screen? *
A. 10 micro-sec B. 20 micro-sec C. 40 micro-sec D. 30 micro-sec
141) Dijkstra’s Banker's Algorithm require the system to maintain the resource information for
each process, including: *
A. The number of resources currently acquired by the process
B. Both The maximum resources that can be requested and The number of resources currently acquired by
the process
C. A count of the system's total resources
D. The maximum resources that can be requested by the process
142) The scheduling strategy where each process in the queue is given a certain amount of
time. After this time has elapsed, the process is preempted and added to the end of the ready
queue is referred to as: *
A. Prioritization B. LIFO C. All of the other choices D. Round-Robin
143) ____ is the partitioning of a single server, each of which can support a different operating
system. *
A. Multiprocessing B. Shared processing C. Virtualization D. Multithreading
144) Failure to lock database records before updating them may result in a ____ between
processes *
A. Deadlock B. Livelock C. Struggle D. Race
145) Assume jobs A-D arrive at almost the same time in the READY queue. Determine the
average turnaround time for Round Robin scheduling (quantum=2). Ignore process switching
overhead. Job: A B C D; CPU cycle: 5 2 6 4 *
A. 10.5 B. 12.5 C. 9.0 D. 5.5
146) Which RAID level duplicates all the disks? *
A. 4 B. 2 C. 1 D. 3
147) Where should be put the page replacement algorithm In Mach model of Page fault
handling with an external pager? *
A. In the low-level MMU handler
B. All of the other choices
C. In the external pager running in user space
D. In the page fault handler that is part of the kernel
148) In terms of main memory efficiency the method of “Backing up pages dynamically” in
comparison with the method of “Paging to a static swap area” is *
A. Nearly equal B. Equal C. Worse D. Better
149) Which is space efficiency, if 4KB-file using file system with 8KB-block? *
A. 75% B. 50% C. 100% D. 25%
A. single-user, single-task B. multiuser C. real-time D. single-user, multitask

151) In modern printing systems, a disk accepts output from several users, Deadlock occurs
when ____. *
A. Too many users attempt to access the printer at the same time.
B. The printer needs all of a job’s output before it will begin printing, but the spooling system fills the
available disk space with only partially completed output.
C. The network connection for the printer overflows with too many requests to use the printer.
D. The buffer fills up with too many print jobs and the printer cannot decide which one to print.
152) Which RAID level employs a Hamming code to correct single bit errors and detect double
bit errors? *
A. 2 B. 1 C. 3 D. 4
153) Consider an i-node, which contains 10 direct addresses of 4 bytes each and all disk blocks
are 1 KB. Also, consider that the i-node contains an additional “single indirect address” that is
used for containing more disk block addresses. What is the largest possible file? *
A. 264 KB
B. 266 KB
C. 262 KB
D. 268 KB
154) Consider the following state of a system with four processes, P1, P2, P3 and P4, and five
types of resources RS1, RS2, RS3, RS4 and RS5 as figure below. Deadlocked processes are: *
1 point
A. P1, P4
B. P3, P4
C. P1, P2
D. P1, P3
155) What is the correct approach with the “No preemption condition” to prevent Deadlock? *
A. Order resources numerically B. Spool everything
C. Take resources away D. Request all resources initially
156) One of way to prevent a deadlock is ________ *
A. Spool everything B. Kills one of the processes
C. Locks one of the processes D. Rollback
157) Which ways are used to keep track of free block in disk space management? *

B. Both linked list method and bitmap method
C. A linked list method
D. A bitmap method
158) The Joliet Extensions provide ________ *
A. Long file name supported Unicode character
B. All of the other choices
C. Directory nesting deeper than 8 levels
D. Directory names with extensions
159) Which is the maximum partition size, if the FAT type is FAT-32 and the block size is 4
KB? *
A. 1 TB B. 256 MB C. 128 MB D. 512 MB
Assume that the disk head is initially at cylinder 37. Which the ordering cylinder in progress
do using a SSF algorithms? *
A. 37 38 40 2 20 10 6 22
B. 37 38 40 2 6 10 20 22
C. 37 10 22 20 2 40 6 38
D. 37 38 40 22 20 10 6 2
161) Which deadlock condition does “Take resources away” attack? *
A. Mutual exclusion
B. No preemption
C. Hold and wait
D. Circular-wait condition
162) Which deadlock condition does “Request all resources initially” attack? *
A. Hold and wait
B. Circular-wait condition
C. Mutual exclusion
D. No preemption
163) A computer uses a programmable clock in square-wave mode. If 500 MHz crystal is used,
what should be the value of the holding register to achieve a clock resolution of 10 msec
(Clock tick)? *
A. 500,000
B. 50,000
C. 50,000,000
D. 5,000,000
A. Immediately following the master file directory
B. The outermost part
C. The innermost part
D. Stored at the beginning of the volume

165) Which is not a goal of a scheduling algorithm for batch systems? *
A. Throughput
B. Response time
C. CPU utilization
D. Turnaround time
166) Dual-layer, double-sided DVD can hold ____ . *
A. 17 GB
B. 9.4 GB
C. 8.5 GB
D. 4.7 GB
167) The methods determine where page is on the disk when it is paged out is *
A. Backing up pages dynamically
B. Paging to a static swap area
C. Both Paging to a static swap area and Backing up pages dynamically
168) Which solutions are used to solve the shared libraries? *
A. Static reallocation and position-independent code
B. Position-independent code
C. Relocation on the fly and position-independent code
169) A system has five processes and three allocated resources. The current allocation and
maximum needs are as following figure. What is the smallest value of x for which this is a safe
state? *
1 point
A. 1
B. 2
C. 3
D. 0

170 )A disk queue with requests for I/O blocks on cylinders in orders: 10, 22, 20, 2, 40, 6, 38.
Assume that the disk head is initially at cylinder 20. How many cylinder do Total head
movement using FCFS? *
A. None of the others B. 146 C. 58 D. 60
A. With an incorrect I/O request
B. That was not in secondary storage
C. That was outside the memory boundaries
D. That was not in main memory
have estimated running times of 8, 6, 2, 10, and 4 minutes. Determine the average waiting time
for FCFS scheduling. Ignore process switching overhead. *
A . 18 minutes B.17 minutes C. 12,8 minutes D. 18.8 minutes
173) The scheme of ____ removes the possibility of a circular wait and therefore guarantees
the removal of deadlocks. *
A. Requesting all resources before job run B. Saving and restoring job state
C/ Preemption D. Hierarchical ordering
174) Which is not attribute of MS-DOS file? *
A. Lock B. Archived C. Read-Only D. Hidden, System
175) A simple structuring model for monolithic system includes: *
A. A main program that invokes the requested service procedure
B. A set of utility procedures that help the service procedures
C. All of the other choices
D. A set of service procedures that carry out the system calls
176) An operation concerning Stable Storage is: *
A. Crash recovery B. All of the other choices C. Stable Reads D. Stable writes
177) VMware Workstation is: *
A. Guest Operating system B. Type 1 Hypervisor C. Host Operating system D. Type 2 Hypervisor
178) Some systems increase the priority of jobs that have been in the system for an unusually
long time to expedite their exit, which is known as ____.? *
A. Aging B. Bumping C. Accelerated priority D. Lagging
179) Which of the following environments preemption is essential? *
A. Batch B. Real time C. Interactive D. None of the other choices
average turnaround time for priority scheduling. Ignore process switching overhead. *
A. 18.8 minutes
B. 16.8 minutes
C. 6 minutes
D. 12.8 minutes

ĐỀ 3 MINH
181) A directory in UNIX/Linux consists of the following *
A. i-node number and file name
B. file name, file size, location of the file on disk
C. file name, file size, location of the file on disk, date created, owner ID
D. none of the other choices
182) A paging system where page size is 2^12 words and the physical memory contains 2^24
words, what is the length of the physical address? *
A. 32 bits B. 16 bits C. 24 bits D. 36 bits
183) If in a resource-allocation graph, each resource type has exactly one instance, which of
the following indicates a deadlock situation? *
A. The graph has no cycle
B. The graph is not connected
C. The graph has at least one cycle
D. The graph is connected
184). In the hierarchical structure for managing, I/O, which layer is closest to the hardware? *
A. Device-independent OS software B. Interrupt handlers
C. Device drivers D. None of the other choices
185) What kind of I/O devices that disks and tapes belong to? *
A. Block-oriented devices B. None of the other choices
C. Character-oriented devices D. Stream-oriented devices
186. The language of the CPU is known as its *
A. Control unit set
B. Instruction set
C. Register set
187) The interface between the operating system kernel and the user programs is defined by
the set of ___ that the operating system provides *
A. System calls B. Functions C. Processes D. Threads
188) Which of the following statements about interrupts and system calls is incorrect? *
A. System calls are caused by internal (synchronous) events
B. Interrupts are caused by external events
C. Interrupts are asynchronous
A. thread B. program C. subprocess D. miniprocess

190) A possibility of deadlock can occur: *
A. If a system is in instable state B. If a system is in unsafe state
B. None of the other choices D. If a system is in safe state
191) When a virtual memory system manages memory in fixed length units, which of the
following terms correctly represents its unit? *
A. IO devices B. Segment C. Page D. Frame
192) What happens when a thread calls Down ( S ) when it wants to enter its critical section,
where S is a binary semaphore set to 1? *
B. The thread is allowed to enter its critical section and S is decremented
C. The semaphore is set to 2
D. The thread is blocked and added to a queue of waiting threads
193) Which statement about DMA is incorrect? *
A. The controller does not need to wait for the CPU to transfer data to/from memory
B. It is always true that DMA is less expensive than CPU-mediate data transfers
C. The CPU needs not to be concerned with the time it takes to transfer data
D. The CPU can start a DMA block transfer, and in the mean time do other work
A. the innermost part
B. stored at the beginning of the volume
C. the outermost part
D. immediately following the master file directory
A. Peterson’s algorithm B. Semaphores
C. Lock variables D. Strict alternation
Programmed I/O? *
A. Memory-mapped I/O is a way to control the device
B. Programmed I/O is a way to actually carry out the I/O operations
D. Programmed I/O may use memory-mapped I/O to fulfill the I/O tasks
A. Inherently conservative strategy
C. Widely used in modern operating systems
D. Relying on ability to predict effect of satisfying allocation requests

198) Which of the following information bits used by the various page replacement policies
indicates if the page has been called lately? *
A. Referenced bit
B. Status bit
C. Locality bit
D. Modified bit
each process, including: *
A. The maximum resources that can be requested by the process
B. The maximum resources that can be requested by the process AND The number of
resources currently acquired by the process
C. The number of resources currently acquired by the process
D. A count of the system’s total resources
200) In general, which is the best technique for I/O Data transfer? *
A. Programmed I/O B. None of the other choices
C. Direct Memory Access D. Interrupt-Driven I/O
Which of the following is a preemptive scheduling algorithm *?
B. FCFS
C. Round Robin
D. Shortest Job First
201) Consider an i-node which contains 10 direct addresses of 4 bytes each and all disk blocks
are 1 KB. Also consider that the i-node contains an additional “single indirect address” that is
used for containing more disk block addresses. What is the largest possible file? *
A. 262 KB B. 266 KB C. 264 KB D. 268 KB
(TLB)? *
A. A TLB miss implies a disk operation will follow
B. A TLB is sometimes known as an associative memory
D. Each entry of a TLB contains the information about one page, including the virtual page
203) A fetched instruction is normally loaded into *
A. Program Counter B. Accumulator
C. None of the other choices D. Instruction Register
204) What is the correct approach with the Mutual Exclusion condition to prevent Deadlock? *
A. Request all resources initially B. Order resources numerically
C. Spool everything D. Take resources away

A. In theory, a program can disable interrupts when it enters a critical section, and re-enable
interrupts when finished with a critical section, to eliminate race conditions.
B. Disabling/enabling interrupts may negatively affect the I/O system.
C. User-mode programs are the best place to invoke disable Interrupt().
D. Programs with infinite loops in their critical sections are a significant problem with the
interrupt-based approach.
207) The special files are: *
A. character special files and block special files
C. block special file
D. character special file
208) An example of the key differences that can exist across (and even in) classes of I/O
devices is: *
A. Data representation
B. Data rate
C. Error conditions
209) Which RAID level employs a Hamming code to correct single bit errors and detect double
bit errors? *
A. 1 B. 2 C. 3 D.4
210) Which of the following is a hardware solution to the critical region problem? *
A. None of the other choices B. Semaphore
C. TSL D. Shared memory
A. ready -> running B. blocked -> ready
C. running -> ready D. blocked -> running
212) Which of the following is true about the block size in disk space management *
A. the larger the block size, the worse the disk space utilization
B. the larger the block size, the lesser the disk space
C. the larger the block size, the lower the data rate
D. none of the other choices
A. Indexed block allocation
B. Contiguous block allocation
C. Sparse block allocation
D. Linked list block allocation

A. Having two modes of operation helps prevent user programs from accessing critical
instructions
B. In kernel mode, the OS can execute every instruction in the instruction set
C. In user mode, user program can execute only a subset of instructions
A. locks one of the processes B. kills one of the processes
C. rollback D. preempt a resource
217) Which of the following is specified to indicate the directory where the file is located? *
A. Sub-directory B. Path name
C. Extension D. Root directory
218) Which of the following statements is not correct about DMA? *
A. DMA controller has access to the system bus independent of the CPU
B. The operating system can only use DMA if the hardware has a DMA controller
C. DMA helps reduce the number of interrupts (in comparison with interrupt-driven I/O)
D. DMA controller is usually faster than CPU
219) When there is an excessive amount of page swapping between main memory and
secondary storage, the operation becomes inefficient, which is called ____. *
A. thrashing B. over swapping
C. hot swapping D. excessive demand paging
K, 4 K, 20 K, 15 K, 9 K. Assume first fit algorithm is used. Which holes are taken for
A.9 K, 15 K, 10 K
B.10 K, 20 K, 15 K
C.20 K, 15 K, 4 K.
D.None of the others
221) A file is generally defined to be: *
A. A collection of similar records
B. A collection of related fields
D. A basic element of data
have estimated running times of 8, 6, 2, 10, and 4 minutes. Determine the mean process
average turnaround time for FCFS scheduling. Ignore process switching overhead. *
A. 18.8 minutes B. 18 minutes C. 19 minutes D. 17 minutes
223) In a single processor system, mutual exclusion can be guaranteed by: *

A. Interleaving processes B. Disabling interrupts
C. All of the other choices D. Overlapping processes
224) Which of the following is appropriate to release page table and pages? *
A. Process creation B. Process execution
C. Page fault time D. Process termination time
225) Which of the following is not a condition for deadlocks? *
A. Preemption B. Hold and Wait
C. Circular Wait D. Mutual exclusion
226) A system has four processes and five allocated resources. The current allocation and need
are as following figure. What is the smallest value of x for which this is a safe state? *
1/1
A. 3 B. 1 C. 2 C.0
227) The ___ is the essential component of the operating system that remains in RAM when
your computer is powered on. *
A. core B. system file C. registry D. kernel
228) ____ is when, in modern printing systems, a disk accepts output from several users and
acts as a temporary storage area for all output until the printer is ready to accept it. *
A. Spooling B. Buffering C. Spoofing D. Lagging
229) Which is NOT a file attribute? *
A. Owner B. Shape C. Size D. Time of Access
230) Which of the following is not a CPU scheduling criterion? *
A. Burst time
B. Response time
C. Throughput
D. CPU utilization
231) If there are 64 pages and the page size is 2048 words, what is the length of logical
address? *
A. 15 bits B. 17 bits C. 14 bits D. 16 bits

A. Prevention B. Deterrence C. Detection D. Avoidance
A. Interactive B. Embedded C. Real-time D. Hybrid
234) Page replacement algorithms determine *
A. how many pages should be added to main memory
B. when the system should update page table entries
C. which pages should be brought into memory because a process is likely to reference them
soon
D. which page to remove to provide space for an incoming page
A. 9 K, 15 K, 10 K B. None of the other choices
C. 20 K, 15 K, 4 K D. 10 K, 20 K, 15 K
236) Which strategy is used in the Banker’s algorithm for dealing with deadlocks? *
A. Deadlock avoidance B. Deadlock ignorance
C. Deadlock detection D. Deadlock prevention
237) The modified/dirty bit is used for the purpose of: *
A. Dynamic allocation of memory used by one process to another
B. Reduce the average time required to service page faults
D. Implementing FIFO page replacement algorithm
238) ____ is the act of allowing only one process to have access to a dedicated resource *
A. No preemption B. Circular wait
C. Mutual exclusion D. Resource holding
239) The two basic types of processor registers are: *
A. Control and status registers
B. General and special registers
D. User-visible and user-invisible register
A. Using memory-mapped I/O, caching a device control register is not acceptable
C. Since the control registers of devices are mapped into the memory space, device drivers
D, Since there is only one address space, all I/O devices must examine all memory references
to see which ones to response to

241) Multiprogramming increases processor efficiency by *
A. Eliminating all idle processor cycles
B. Taking advantage of time wasted by long wait I/O handling
D. Increasing processor speed
ĐỀ 2 MINH
241) Which is a wrong statement about the quantum used in Round Robin algorithm? *
A. If the quantum is very large, RR is essentially FCFS
B. A reasonable value of quantum is around 20-50 ms
C. If the quantum is very small, the CPU efficiency is reduced
242) What are the allocation methods of disk blocks for files: *
A. Linked allocation
B. Contiguous allocation
D. Indexed allocation
243) Assume jobs A-D arrive in quick succession in the READY queue. Using round robin
A. 5 B.20 C. 18.25 D.73
244) What is interrupt vector? *
A. Part of memory which contains the addresses of interrupt handlers
B. A signal an I/O device sends to CPU
D. A signal CPU sends to I/O device
B. In user mode, user program can execute only a subset of instructions
C. Having two modes of operation helps prevent user programs from accessing critical
instructions
D. In kernel mode, the OS can execute every instruction in the instruction set
246) Which of the following statements about the CPU’s handling interrupts is incorrect? *
B. The CPU branches to a new instruction sequence
C. The processor ceases to execute the current sequence of instructions

D. The hardware saves the old PC location
247) Which strategy is used in the Banker’s algorithm for dealing with deadlocks? *
A. Deadlock prevention B. Deadlock ignorance
C. Deadlock avoidance D. Deadlock detection
248) Which deadlock condition does order resources numerically attack? *
A. Mutual exclusion B. No preemption
C. Hold and wait D. None of the other choices
each process, including (choose 1 answer only): *
A count of the system’s total resources
The maximum resources that can be requested by the process
The maximum resources that can be requested by the process and The number of resources
currently acquired by the process
The number of resources currently acquired by the process
250) Which of the following statements is incorrect about I/O using DMA? *
DMA helps free up the CPU during the I/O to do other work
In essence, DMA is programmed I/O, except the fact that DMA, instead of the CPU, does all
the work
DMA helps reduce the number of interrupts
None of the other choices
251) The I/O technique where the processor busily waits for an I/O operation to complete is
called: *
Direct Memory Access (DMA)
Interrupt-driven I/O
Programmed I/O
252) A table in main memory storing linked list allocation of disk blocks is called: *
File list table Disk allocation table
Linked list table File allocation table
single-user, single-task
single-user, multitask
real-time
multiuser
rollback
kills one of the processes
preempt a resource
locks one of the processes

255) The special files are (choose 1 answer only): *
character special file
none of the other choices
character special files and block special files
block special file
257) In general, which is the best technique for I/O Data transfer? *
Programmed I/O
Direct Memory Access
Interrupt-Driven I/O
1/1
1
33
4033
4000
259) Which of the following is not correct about hard links and symbolic links? *
Hard links do not require extra disk space
Symbolic links can point to files in the network
Symbolic links need space to store the name of the file pointed to
Hard links can point to files on other machines
K, 4 K, 20 K, 15 K, 9 K. Assume worst fit algorithm is used. Which holes are taken for
9 K, 15 K, 10 K
10 K, 20 K, 15 K
20 K, 15 K, left over of 20 K

261) A computer has four page frames. The time of loading, time of last access, and the R and
M bits for each page are as shown below (the times are in clock ticks). Which page will
Second Chance replace? *
1/1
3
1
0
2
In theory, a program can disable interrupts when it enters a critical section, and re-enable
Programs with infinite loops in their critical sections are a significant problem with the
interrupt-based approach
Disabling/enabling interrupts may negatively affect the I/O system
User-mode programs are the best place to invoke disableInterrupt()
Correct answer
In theory, a program can disable interrupts when it enters a critical section, and re-enable
263) In a directed graphs model, a possible of deadlock can occur: *
If graph contains a cycle and only one instance per resource type
If graph contains no cycle
None of the others
If graph contains a cycle and several instances per resource type
264) ____ is the partitioning of a single server, each of which can support a different
operating *
Multiprocessing
Multithreading

Virtualization
Shared processing
265) Which of the following statements about segmentation is false? *
Sharing of procedures between different users can be facilitated
The total address space can be more than the size of physical memory
There are several linear address spaces
Using memory-mapped I/O, caching a device control register is not acceptable
Since the control registers of devices are mapped into the memory space, device drivers can
be written without using Assembly language
Since there is only one address space, all I/O devices must examine all memory references to
see which ones to response to
267) Which of the following actions generates an external interrupt? *
A system call instruction is executed.
A page that does not exist in the main memory is accessed by the virtual storage management.
Division by zero occurs.
An input/output operation is completed.
268) Working set model is used for: *
All of the other choices
Determining whether page replacement is needed
Finding the minimum number of frames necessary for a job so that jobs can be run without
“thrashing”
Finding the average number of frames a job will need to run smoothly
269) Information that must be saved prior to the processor transferring control to the interrupt
handler routine includes: *
PSW
PSW and PC
PSW and Contents of processor registers
270) Which part of a disk is used to boot the computer? *
Super block
Root block
Boot block
MBR

271) Linux and __________ are often used as operating systems on supercomputers,
mainframes, and servers. *
Mac OS UNIX
None of the other choices Windows
272) Which mechanism is described as “the device controller sneaks in and steals an
occasional bus cycle from the CPU once in a while, delaying it slightly”? *
Cycle sneaking Cycle stealing
Interrupt stealing All of the others
273) Which of the following statements about semaphores is true? *
P and V (Down and Up) operations should be indivisible operations
All of the other choices
If several processes attempt a P(S) operation simultaneously, only one process should be
allowed to proceed
A semaphore implementation should guarantee that processes do not suffer indefinite
postponement
mean process average turnaround time for priority scheduling. Ignore process switching
overhead . *
10,8 minutes
12,8 minutes
16,8 minutes
54 minutes
Avoidance
Deterrence
Prevention
Detection
276) What is not correct about contiguous allocation of files? *
It leads to excellent read performance
It is widely used on CD-ROMs

It is simple to implement
It does not cause disk fragmentation
Real-time
Embedded
Interactive
Hybrid
278) What is the weakness of the Banker’s algorithm? *
Allowing the population of processes to vary over time
Enabling the number of resources to fluctuate
Enabling processes to hold their resources indefinitely
Requiring that processes state their maximum needs in advance
Programmed I/O? *
Programmed I/O may use memory-mapped I/O to fulfill the I/O tasks
Memory-mapped I/O is a way to control the device
Programmed I/O is a way to actually carry out the I/O operations
Correct answer
280) Which of the following is a preemptive scheduling algorithm *
Shortest Job First
FCFS
Round Robin
281) In which of the following environments preemption is essential? *
Interactive
Real time
Batch
9 K, 15 K, 10 K

10 K, 20 K, 15 K
20 K, 15 K, 4 K
Indexed block allocation
Sparse block allocation
Contiguous block allocation
Linked list block allocation
284) Which of the following is not correct about the reliability of different RAID levels? *
1/1
In RAID levels 3, 4, 5 a single bit error in a word can be detected
There is no reliability support in RAID level 0
In RAID level 2, a single bit error in a word can be detected AND corrected
All RAID levels can survive one disk crash
1/1
miniprocess
subprocess
program
thread
286) With paging, when is the internal fragmentation possible? *
Page does not fit the frame
The virtual memory assigned to the program is less than the physical memory assigned to it
Such thing cannot happen
The last page of the job is less than the maximum page size
(TLB)? *
TLB only maintains a subset of the entries stored in the full memory-based page table
The use of TLB eliminates the need for keeping a page table in memory
288) When there is a TLB miss the system needs to access the page table
A directory in UNIX/Linux consists of the following *
i-node number and file name
file name, file size, location of the file on disk, date created, owner ID
File name, file size, location of the file on disk

that was not in main memory
that was outside the memory boundaries
that was not in secondary storage
with an incorrect I/O request
290 ) Which of the following statements is incorrect about Translation Look-aside Buffer
(TLB)? *
A TLB is sometimes known as an associative memory
A TLB miss implies a disk operation will follow
Each entry of a TLB contains the information about one page, including the virtual page
Assume that the disk head is initially at cylinder 9. How many cylinder do total head
67
43
45
None of the others
Inherently conservative strategy
Widely used in modern operating systems
Relying on ability to predict effect of satisfying allocation requests
293) Consider the following state of a system with four processes P1, P2, P3 and P4 and five
types of resources RS1, RS2, RS3, RS4 and RS5 as figure below. Deadlocked processes are
___ *
1/1

P2, P3
P1, P2
P1, P3
P1, P4
294) Which of the following statements about interrupts and trap instructions is incorrect? *
A trap instruction is a software-generated interrupt
An interrupt is a hardware-generated change of control flow within the system
An interrupt handler deals with the cause of the interrupt
All deadlocks involve conflicting needs for resources by *
One or more processes
Two or more processes
Three or more processes
Strict alternation
Lock variables
Peterson’s algorithm
Semaphores
the outermost part
stored at the beginning of the volume
immediately following the master file directory
the innermost part
blocked -> ready blocked -> running
running -> ready ready -> running
298) Which of the following is a hardware solution to the critical region problem? *
TSL None of the other choices
Semaphore Shared memory
299) Which of the following is specified to indicate the directory where the file is located? *
Path name Extension
Sub-directory Root director
300 )Which of the following conditions of semaphore variable “s” implies a busy critical
region? *
1/1
s = 0 s > 0 s < 0 None of the other choices

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