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CUSTOMER_CODE
SMUDE
DIVISION_CODE
SMUDE
EVENT_CODE
APR2016
ASSESSMENT_CODE MIT201_APR2016
QUESTION_TYPE
DESCRIPTIVE_QUESTION
QUESTION_ID
16029
QUESTION_TEXT
a.What are category’s of major security threats and types of viruses.
b.Explain basic types of MOS
SCHEME OF
EVALUATION
Major threats to security are categorized as:
Tapping
Disclosure
Amendment
Fabrication
Denial
(2 marks)
Types of viruses:
Boot sector infectors
Memory Infectors
File specific Infectors
Command processor Infectors
General purpose infectors
(2 marks)
Basic types of Multiprocessor Operating Systems(MOS) are:
Separate supervisors
Master/slave
Symmetric
Separate supervisors: Here each node is a processor having a separate
operating system with memory and I/O resources. Addition of few
additional services and data structures will help to support aspects of
multiprocessor
(2 marks)
Master/slave: In this approach, one processor the master is dedicated to
execute the operating system, the remaining processors are slaves and
form a pool of computational processors. The master schedules and
controls the slaves. This arrangement allows parallelism in an
application by allocating to it many slaves.
(2 marks)
Symmetric: All processors are functionally identical. They form a pool
of resources. Other resources such as memory and I/O devices are
available to all processors. If they are available only to a few then system
becomes asymmetric. The operating system is also symmetric. Any
processor can execute it. The processor which executes the operating
system temporarily is the master
(2 marks)
QUESTION_TYPE
DESCRIPTIVE_QUESTION
QUESTION_ID
16030
QUESTION_TEXT
Write a note on Module Kernel
SCHEME OF
EVALUATION
The best current methodology for operating system design involves
using object-oriented programming techniques to create a modular
kernel. The kernel has a set of core components and dynamically links
in additional services either during boot time or during run time. Such
strategy uses dynamically loadable modules and is common in modern
implementations of UNIX such as Solaris, LINUX and MacOS. For
example the Solaris OS structure is organized around a core kernel with
seven types of loadable kernel modules
(Scheme: 5 marks)
1.Scheduling
2.File Systems
3.Loadable System calls
4.Executable formats
5.STREAMS formats
6.Miscellaneous
7.Device and bus drivers
Such a design allow the kernel to provide core service yet also allows
certain features to be implemented dynamically.
(Scheme: 5 marks)
(Scheme: As above 5 + 5 = 10 marks)
QUESTION_TYPE
DESCRIPTIVE_QUESTION
QUESTION_ID
74195
QUESTION_TEXT
A security system can be attacked in many ways. Discuss some
of them
SCHEME OF
EVALUATION
A security system can be attacked in many ways. Some of them
are
1. Authentication: Explain
(Scheme: 3 marks)
2. Browsing
3. Invalid parameters
4. Line tapping
5. Improper Access controls
(Scheme: 2 to 5 1 mark each = 4 marks)
6. Rogue software: Explain
(Scheme: 3 marks)
(Scheme: As above 3+4+3 = 10 marks)
QUESTION_TYPE
DESCRIPTIVE_QUESTION
QUESTION_ID
74200
QUESTION_TEXT
Give and explain I/O structure.
SCHEME OF
EVALUATION
The I/O controllers and main memory are connected to the main system
bus. The cache memory (usually found on-chip with the CPU) has a
direct connection to the processor, as well as to the system bus.
The I/O devices shown here are not connected directly to the system bus;
they interface with another device called an I/O controller. In simpler
systems, the CPU may also serve as the I/O controller, but in systems
where throughput and performance are important, I/O operations are
generally handled outside the processor.
Until relatively recently, the I/O performance of a system was somewhat
of an afterthought for systems designers. The reduced cost of highperformance disks, permitting the proliferation of virtual memory
systems, and the dramatic reduction in the cost of high-quality video
display devices, have meant that designers must pay much more
attention to this aspect to ensure adequate performance in the overall
system.
Because of the different speeds and data requirements of I/O devices,
different I/O strategies may be useful, depending on the type of I/O
device which is connected to the computer. Because the I/O devices are
not synchronized with the CPU, some information must be exchanged
between the CPU and the device to ensure that the data is received
reliably. This interaction between the CPU and an I/O device is usually
referred to as “handshaking''.
(10 marks)
QUESTION_TYPE
DESCRIPTIVE_QUESTION
QUESTION_ID
118250
QUESTION_TEXT
Explain Direct and Indirect Communication. How the send and receive
primitives are defined and what are the properties of communication link
in Direct and Indirect Communication.
Direct Communication:
SCHEME OF
EVALUATION
In the direct–communication discipline, each process that wants to
communicate must explicitly name the recipient or sender of the
communication. In this scheme, the send and receive primitives are
defined as follows:
Send (P, message). Send a message to process P.
Receive (Q, message). Receive a message from process Q.
A communication link in this scheme has the following properties:
A link is established automatically between every pair of processes that
want to communicate. The processes need to know only each other's
identity to communicate.
A link is associated with exactly two processes.
Between each pair of processes, there exists exactly one link.
The link may be unidirectional, but is usually bi–directional. (5 Marks)
Indirect Communication:
With indirect communication, the messages are sent to and received
from mailboxes (also referred to as ports). A mailbox can be viewed
abstractly as an object into which messages can be placed by processes
and from which messages can be removed. Each mailbox has a unique
identification. In this scheme, a process can communicate with some
other process via a number of different mailboxes. Two processes can
communicate only if the processes have a shared mailbox. The send and
receive primitives are defined as follows:
send (A, message). Send a message to mailbox A.
receive (A, message). Receive a message from mailbox A.
In this scheme, a communication link has the following properties:
A link is established between a pair of processes only if they have a
shared mailbox.
A link may be associated with more than two processes.
Between each pair of communicating processes, there may be a number
of different links, each link corresponding to one mailbox.
A link may be either unidirectional or bi–directional. (5 Marks)
QUESTION_TYPE
DESCRIPTIVE_QUESTION
QUESTION_ID
118254
QUESTION_TEXT
What is centralized data? Explain the functions of NOS?
Definition of centralized data (2 Marks)
Functions of NOS
i.
Redirection
ii.
Communication management
iii.
File/printer services
iv.
Network management (8 Marks)
SCHEME OF EVALUATION