Exam Questions

Question 1

What size quantum should you use for round robin and why? What is the relationship between size of quantum and context switching?

Answer 1

This has issues as switching processes wastes time. Setting quantum to long means slow response. Good rule is 20-50ms. Short quantum - good for interactive systems, good response, poor throughput Long quantum - good for batch systems, bad response, good throughput

Question 2

Explain components of virtual addresses, know how to map virtual and physical pages, what is layout of virtual and physical memories? How big is page table? Be able to do calculations

Answer 2

Last bits are for page size and frame size, the remaining bits are the numbers of pages and frames. Last bits being those in the offset range. So if we remove any offset values, we can then say that what’s left is the page number. This is index into page table. Number of page table entries = (Number of bits in physical address - offset) bits

Question 3

Explain Diagram of Virtual Memory

Answer 3

You have a screenshot of this. Beginning of lecture on April 8

Question 4

Calculate number of page faults

Answer 4

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Question 5

What’s the relationship between the working set and the size of the page? What sort of page size would you use?

Answer 5

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Question 6

Access modify change times - what’s going on? Using stat command

Answer 6

lab task

Question 7

structure of files

Answer 7

the boot block (block 0): contains code to bootstrap the system the super block (block 1): contains summary information for the file system (where to find everything else) blocks for a fixed number of inodes blocks for file data (each block contains a fixed number of disk sectors) read tannebaum

Question 8

how do we use chmod and how do we change read write execute permissions in unix

Answer 8

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Question 9

What happens if i change permission on directory to non execute

Answer 9

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Question 10

What is going on with ssh? How do i log into dimefox?

Answer 10

ssh dimefox.eng.unimelb.edu.au`

Question 11

What is the max possible file size in bytes of the linux ext2 file system given: 10 data blocks with direct addresses 1 single indirect block 1 double indirect block 1 triple indirect block Assume disk blocks are 1KB and pointes to disk blocks are 4 bytes

Answer 11

Use screencap Sun 5 july 4:05pm. 10*1KB: 10KB 1KB + 8 bytes… google

Question 12

Write Dekker’s algorithm and explain it

Answer 12

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Question 13

Protocol stack

Answer 13

do lab tasks

Question 14

define packet switching, speak about pros and cons

Answer 14

see other cards

Question 15

http is a protocol. so when you enter an address how does it get to your machine?

Answer 15

contact dns server to get IP address or resource, then displays requested file. …… …..

Question 16

OSI reference model

Answer 16

Operation Systems Interconnection. - layer should be created where a different abstraction is needed - each layer should perform a well defined function (identify this in snippet of c code) - function of each layer should be chosen with a view toward defining internationally standardised protocols - layer boundaries should be chosen to minimise information flow across interfaces - number of layers should be large enough that distinct functions need not be thrown together in same layer out of necessity and small enough that architecture doesn’t become too unwieldy

Question 17

ive got this particular implementation of these layers. the layer has to be at tcp layer. tcp provides whole lot of functionality for me. why do i have to do that? why cant i just provide part of that functionality at lower level? at IP level?

Answer 17

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Question 18

Talk about the different address which are available to components or devices

Answer 18

host and network layers

Question 19

expected to manipulate 32 bit IP address

Answer 19

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Question 20

When you click on a link what happens

Answer 20

lec 1

Question 21

Explain this diagram

Answer 21

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Question 22

What would you expect to see in page table entry?

Answer 22

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Question 23

We have a stream of pages that need to be loaded into x frames. I have a limited number of frames. How can we eject pages using FIFO? How many page faults occur?

Answer 23

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Question 24

How do i manage free space (file)

Answer 24

structure of files.

Question 25

structure of file system

Answer 25

array,