OS sse

are rigid metal or glass platters covered with magnetic recording material.

Disks

In a disk the information is recorded on the __

surface

It is a way to read and write data on disks, where the density of bits (bits/unit length) per track is uniform.

Constant Linear Velocity

It is the time it takes to actually transfer data between disk and main memory.

Transfer time

A _ has a separate read-write head for each track.

Fixed-head system

Each disk platter has a flat _ shape, like a phonograoh record.

circular

The system stores information by recording it on the sector under the read-write head.

magnetically

Which of the given is considered aspects of disk management for which an operating system is responsible.

all of these (Booting from disk, Bad-block recovery, disk formatting)

A typical hard disk have a rotation speed from __

4500 to 7200

Modern disks are addressed as large one-dimensional arrays of logical blocks, where the is the smallest unit of transfer.

logical block

Since most jobs depend heavily on the disk for loading and input and output files, it is important that disk service be as fast as possible.

True

In C-SCAN scheduling, when it reaches the other end, it immediately returns to the beginning of the disk without servicing any requests on the return trip.

True

The OS can improve on the average disk service time by scheduling the requests for disk access.

True

C-SCAN scheduling essentially treats the disk as though it were circular where the last track is adjacent to the first one.

True

The First Come First Served disk scheduling selects the request according to the order in the disk queue

True

It provides the bulk of secondary storage for modern computer systems.

Magnetic Disk

A disk normally has a device _ indicating which files are on the disk.

directory

A disk system has several disk platters.

Magnetic

These disks are coated with a hard surface, so the read-write head scans it directly on the disk surface without destroying the data.

floppy disks

The disk surface is logically divided into _, which are subdivided into sectors.

tracks

It is a way to read and write data on disks, where the number of bits per track is uniform (constant number of sectors).

Constant Angular Velocity

_ was used as an early secondary-storage medium, but the access time is much slower than for disks.

Magnetic Tape

LOOK disk scheduling algorithm is sometimes called the elevator algorithm

F (SCAN)

The Shortest Seek Time First disk scheduling selects the request with the maximum seek time from the current head position.

F (minimum)

A movable-head system has only one read-write head per surface and the system moves the head to access a particular track

Movable-Head system

It is the time it takes for the sector to rotate under the head.

Latency time

The main requirement of secondary storage is to be able to store very large amount of data _

permanently

One or more blocks that are unreadable or not writable

Bad block

It is the time it takes to move the read-write head to the correct track.

Seek time

An incident where the head contacts the disk surface, the head will scrape the recording medium off the disk.

Head crashes

The size of a logical block is usually ____ bytes.

512

The Look disk scheduling selects the request with the minimum seek time from the current head position.

F (SSTF)

The Shortest Seek Time First disk scheduling selects the request with the minimum seek time from the current head position.

True

“Recovery of essential and full services after attack” is described as _.

Strategies for limiting damage

Computer “Virus” is a vulnerability of Single Computer (without E-mail or internet)

True

Windows 10 is an example of hand-held operating system

F (not an example)

“Sniffers” is a vulnerability of a LAN connected (with internet).

F ( without internet )

__ plays a key role in computer system security.

Operating System

Which of the following example strategies belong to the key property “Adaptation and evolution to reduce effectiveness of future attacks”?

intrusion recognition patterns

“E-mail” is a vulnerability of which configuration?

LAN connected (with internet)

“Adaptation and evolution to reduce effectiveness of future attacks” is described as_.

Strategies for improving system survivability based on knowledge retrieved from attacks.

Which among the given is a vulnerability of a single computer without e-mail or internet?

Compressed Passwords

LAN connected (without internet) is vulnerable to “sniffers”.

True

Infects files on the computer, normally executable files (.exe and .com) commonly found on Microsoft operating systems.

File infector virus

Spoofing is the act of disguising a communication from an unknown source as being from a known, trusted source.

True

Ransomware is a malware that demands a fee or ransom.

True

Small programs written to alter the way a computer operates, without permission of the user.

Virus

Antivirus softwares combat viruses.

True

Hardware malfunction is an example of:

unintentional Intrusion

Spear-phishing is variation of phishing In which the phishier sends fake emails to a certain employee of an organization.

True

Blended threats are considered as intentional attacks.

True

Ransomware is similar to smishing except that the victims receive a voice mail telling them to call a phone number or access a website.

F (vishing)

Spoofing can be applied to emails, phone calls, and websites

True

The more complex and powerful the , the more likely it is to have vulnerabilities to attack.

operating System

Which of the following example strategies does not belong to the key property “Recover of essential and full services after attack”?

all of these (intrusion detection, authentication, encryption)

“Recognition of attacks and damage” is described as .

Strategies for detecting attacks

LAN connected (without internet) is vulnerable to “spoofing”.

True

“E-mail” is a vulnerability of LAN connected (with internet).

True

Which of the given is an example strategy of the key property “Resistance to attacks”?

authentication

Which among the given is not a vulnerability of a LAN connected without internet?

E-mail

What is the “Relative risk” of a LAN connected without internet?

medium

What is the “Relative risk” of a LAN connected with internet?

High

Infects the boot record, the system area of a floppy disk or a hard drive.

Boot sector virus

To be called a virus, one must be self-executing and __.

Self-replicating

Which of the following is an example of an intentional attack?

all of these (Blended Threats, Trojan Horses, Viruses and worms)

Works by attaching itself to a template (such as NORMAL.DOT), which in turn is attached to word processing documents.

Macro Virus

Firewalls are important for security.

True

Any breach of security or modification of data that was not the result of a planned intrusion.

unintentional intrusions

Antivirus software can remove all impurities from your computer.

False (can not)

This infects the boot record of a disk, saving a legitimate copy of the master boot record in a different location on the volume.

Master boot record virus

Refers to the use of discarded materials such as disks, CDs, printout, etc., to enter the system legally.

Trash Collection

Hoax Sites are used when unauthorized users want to disguise themselves as friendly sites.

True

Which among the given is not a vulnerability of a single computer without e-mail or internet?

Sniffers

What is the “ease of protection” of a LAN connected with internet?

low

What is the “Relative risk” of a single computer without e-mail or internet?

low

Which of the configurations is vulnerable to “Spoofing”?

LAN connected with or without Internet

___ must be on guard to arm their operating systems with all available defense against attack

System Administrators

Which of these are the key properties of a survivable system?

all of the above (Recovery of essential services after an attack, Resistance to attacks, Recognition of attacks and resulting damage)

It is when an unauthorized users gain access to search through secondary storage directories or files for information they should not have the privilege to read.

Browsing

A type of virus which is triggered by a specific time

Time Bomb

Spooping is the act of disguising a communication from an unknown source as being from a known, trusted source.

F (Spoofing)

Which of the configurations is vulnerable to “Sniffers”?

LAN connected with or without Internet

“Resistance to attacks” is the same as _.

Strategies for repelling attacks

Which of the following example strategies does not belong to the key property “Resistance to attacks”?

intrusion detection

Which among the given is a vulnerability of a LAN connected with internet?

all of these (E-mail, Spoofing, Viruses)

Written policies and procedures and _ user training are essential elements of system management

regular

Which of the given is an example of unintentional attack?

Hardware malfunction

__ are programs that reside on computers attached to the network.

none of the these (must be sniffers)

Sniffers are programs that reside on computer attached to the network

True

Vishing is a type of phishing that involves the use of short messages service (SMS) texting.

F (smishing)

What is the “ease of protection” of a LAN connected without Internet?

Medium

Which of the given is an example strategy of the key property “Recover of essential and full services after attack”?

contingency planning

Which of the given is an example strategy of the key property “Recognition of attack and damage”?

intrusion detection

Any vulnerability at the _ level opens the entire system to attack.

operating system

virus” is a vulnerability of which configuration?

all of these (Single Computer (without E-mail or internet), Laptop with E-mail, LAN connected with internet)

Which of the following example strategies does not belong to the key property “Recovery of essential and full services after attack”?

authentication

_ is one in which a malicious hacker takes over computers via the internet and causes them to flood a target site with demands for data and other small tasks causing a computer to perform repeated unproductive task.

Denial of Service (DoS) attack

A type of virus which is triggered by a certain event like keystroke

Logic Bomb

Infects data files (such as word processing documents, spreadsheets, etc.)

Macro Virus

These refer to entering systems by guessing authentic passwords.

Repeated trials