OS Viva Expected Questions

8/14/2019 OS Viva Expected Questions

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OPERATING SYSTEMS LABExpected Viva Questions

1. What is an operating system?a. Operating system is an important part of almost every computersystem

2. What are the components present in computer?a. A computer system can be divided roughly into four components,

the operating system, the application programs, and the user.3. What is symmetric multiprocessing?

a. Each processor runs an identical copy of the operating system, andthese copies communicate ith one another as needed.

!ist out the types in mainframe systemsi" #atch systemii" $ultiprogrammed systems

iii" %ime&sharing systemWhat is file&server systems?

i" 'ile&server system provides a file system interfacehere clients can create, update, read, and deletefiles

(. What is )ob scheduling?a. *f several )obs are ready to be brought in to memory, and if there is

not enough room for all of them, then the system must chooseamong them. $a+ing this decision is )ob scheduling.

1. efine non&preemptive schedulingb. 'irst come first serve scheduling -fcfs"c. hortest )ob first scheduling

2. efine dispatcher and its functions?i. itching conte/t ii.itching to user modeii. 0umping to the proper location in the user program to restarts

the program3. efine dispatch latency?

d. %he time ta+en for the dispatcher to stop one process and startanother running process is +non as dispatch latency.

. What is mean by '' scheduling?a. '' also +non as 'irst&in&first&out-'*'O"hich is the simplest

scheduling policy. arriving )obs are inserted into the tail-rear"of the

ready ueue.1. efine 45 scheduling.

b. 45 scheduling is the process of sitching the 45 among variousprocesses. 45 scheduling is the basis of multi programmedoperating systems. #y sitching the 45 among processes, theoperating system can ma+e the computer more productive.

2. What is a ispatcher?c. %he dispatcher is the module that gives control of the 45 to the

process selected by the short&term scheduler. %his functioninvolves6 7 itching conte/t 7 itching to user mode

7 0umping to the proper location in the user program torestart that program.

3. What is turnaround time?


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d. %urnaround time is the interval from the time of submission to thetime of completion of a process.

e. *t is the sum of the periods spent aiting to get into memory,aiting in the ready ueue, e/ecuting on the 45, and doing *8O.

1. What are privileged instructions?f. ome of the machine instructions that may cause harm to a system

are designated as privileged instructions. %he hardare allos theprivileged instructions to be e/ecuted only in monitor mode.

2. 9o can a user program disrupt the normal operations of a system?g. A user program may disrupt the normal operation of a system by

7 *ssuing illegal *8O operations7 by accessing memory locations ithin the O itself7 :efusing to relinuish the 45

3. 9o is the protection for memory provided?%he protection against illegal memory access is done by using toregisters. %he base register and the limit register. %he base registerholds the smallest legal physical address; the limit register contains the

si


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=. What do you mean by first fit?a. 'irst fit allocates the first hole that is big enough. earching can

either start at the beginning of the set of holes or here theprevious first&fit search ended. earching can be stopped as soon asa free hole that is big enough is found.

What is a semaphore? ->O8E @"b. A semaphore BB is a synchroniov8E @I"d. A thread otherise called a lighteight process -!W4" is a basic unit

of 45 utili


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3. !ist the various file attributes.l. A file has certain other attributes, hich vary from one operating

system to another, but typically consist of these6 >ame, identifier,type, location, si


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a. >o e/ternal&fragmentation problem b. solves the siO8E @J" 2@11"aa.A spool is a buffer that holds output for a device, such as printer,

that cannot accept interleaved data streams. When an applicationfinishes printing, the spooling system ueues the correspondingspool file for output to the printer. %he spooling system copies theueued spool files to the printer one at a time.

3. What are the various dis+&scheduling algorithms? -A5&A4:8$AH1@"

bb.%he various dis+&scheduling algorithms area. 'irst ome 'irst erved cheduling b. hortest ee+ %ime 'irst

chedulingb. A> cheduling d. &A> cheduling

cc. e. !OOM scheduling(. What are the different accessing methods of a file?

dd.%he different types of accessing a file are67 euential access6 *nformation in the file is accessed

seuentially7 irect access6 *nformation in the file can be accessed

ithout any particular order.

7 Other access methods6 reating inde/ for the file, inde/edseuential access method -*A$" etc.. What is irectory?

ee.%he device directory or simply +non as directory recordsinformation&such as name, location, si


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1. What is !inu/? !ist the features of !inu/.2. !ist the commands used in !inu/.3. What is hell?(. What is +ernel?. What is process?=. What is synchroni*N?(.What are the 5>*N system calls for *8O?.9o do you change 'ile permissions?=.What are lin+s and symbolic lin+s in 5>*N file system?I.What is '*'O?.9o do you create special files li+e named pipes and device files?J.iscuss the mount and unmount system calls?1@. 9o does the inode map to data bloc+ of a file?11. What is a shell?12. #rief about the initial process seuence hile the system

boots up.


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13. What are various *s associated ith a process?1(. E/plain for+-" system call.1. !ist the system calls used for process management1=. 9o can you get8set an environment variable from a

program?1I. 9o can a parent and child process communicate?1. What is a Qombie?1J. What are the process status in !*>5N?2@. What is the difference beteen process and thread?21. What is the different *4 techniues and give the difference

beteen them.22. What are the orphan process?23. efine 4O*N thread? What are thread attributes?2(. efine emaphore?2. !ist and e/plain classical synchroni

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