bit 3205 system support marking scheme

BIT 3205 System Support

ST. PAUL’S UNIVERSITY

Private Bag 00217 LimuruTel: 020-2020505/510, 0728-669000, 0736-

424440Email: [email protected]

Website: http://www.stpauls-limuru.org

FACULTY OF BUSINESS STUDIESBACHELOR OF BUSINESS & INFORMATION TECHNOLOGY

BIT 3205: SYSTEM SUPPORT

DATE: 16TH AUGUST 2012 TIME: 5.30 PM – 8.30 PM

MARKING SCHEME

Markers are advised that many answers in Marking Schemes are examples only of what might be expected from candidates. Unless a question specifically states that an answer is demanded in a particular form, then an answer, which is, correct, factually or in computing practice, must be given the available marks.

If there is doubt as to the correctness of an answer the recommended textbook should be the first authority. If doubt persists the scripts should be referred to the Examiner and, if necessary to the Moderator, for a second marking.

This Marking Scheme has been prepared as a guide to markers. It does indicate what the examiner was expecting candidates to produce in response to the question set and some questions in some units will only have one correct solution. However, this is NOT ABSOLUTELY a set of model answer; NOR is the Marking Scheme exclusive, for there will frequently be alternative responses which will provide a valid answer.

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SECTION A: COMPULSORY QUESTION {30 MARKS}

QUESTION 1

a. Discuss FIVE types of operating systems (10 Marks)

• Real-time - A real-time operating system is a multitasking operating system that

aims at executing real-time applications. Real-time operating systems often use

specialized scheduling algorithms so that they can achieve a deterministic nature of

behavior. The main objective of real-time operating systems is their quick and predictable

response to events. They have an event-driven or time-sharing design and often aspects

of both. An event-driven system switches between tasks based on their priorities or

external events while time-sharing operating systems switch tasks based on clock

interrupts.

• Multi-user vs. Single-user - A multi-user operating system allows multiple users to

access a computer system concurrently. Time-sharing system can be classified as multi-

user systems as they enable a multiple user access to a computer through the sharing of

time. Single-user operating systems, as opposed to a multi-user operating system, are

usable by a single user at a time. Being able to use multiple accounts on a Windows

operating system does not make it a multi-user system. Rather, only the network

administrator is the real user. But for a Unix-like operating system, it is possible for two

users to login at a time and this capability of the OS makes it a multi-user operating

system.

• Multi-tasking vs. Single-tasking - When only a single program is allowed to run at a

time, the system is grouped under a single-tasking system. However, when the operating

system allows the execution of multiple tasks at one time, it is classified as a multi-tasking

operating system. Multi-tasking can be of two types: pre-emptive or co-operative. In pre-

emptive multitasking, the operating system slices the CPU time and dedicates one slot to

each of the programs. Unix-like operating systems such as Solaris and Linux support pre-

emptive multitasking, as does AmigaOS. Cooperative multitasking is achieved by relying

on each process to give time to the other processes in a defined manner. 16-bit versions of

Microsoft Windows used cooperative multi-tasking. 32-bit versions, both Windows NT and

Win9x, used pre-emptive multi-tasking. Mac OS prior to OS X used to support cooperative

multitasking.

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• Distributed - A distributed operating system manages a group of independent

computers and makes them appear to be a single computer. The development of

networked computers that could be linked and communicate with each other gave rise to

distributed computing. Distributed computations are carried out on more than one

machine. When computers in a group work in cooperation, they make a distributed system.

• Embedded - Embedded operating systems are designed to be used in embedded

computer systems. They are designed to operate on small machines like PDAs with less

autonomy. They are able to operate with a limited number of resources. They are very

compact and extremely efficient by design. Windows CE and Minix 3 are some examples

of embedded operating systems.

b. Discuss FIVE Operating System utility software’s (10 Marks)

• Anti-virus utilities scan for computer viruses.

• Backup utilities can make a copy of all information stored on a disk, and restore

either the entire disk (e.g. in an event of disk failure) or selected files (e.g. in an event of

accidental deletion).

• Data compression utilities output a shorter stream or a smaller file when provided

with a stream or file.

• Disk checkers can scan the contents of a hard disk to find files or areas that are

corrupted in some way, or were not correctly saved, and eliminate them for a more

efficiently operating hard drive.

• Disk cleaners can find files that are unnecessary to computer operation, or take up

considerable amounts of space. Disk cleaner helps the user to decide what to delete when

their hard disk is full.

• Disk compression utilities can transparently compress/uncompress the contents of

a disk, increasing the capacity of the disk.

• Disk defragmenters can detect computer files whose contents are broken across

several locations on the hard disk, and move the fragments to one location to increase

efficiency.

• Disk partitions can divide an individual drive into multiple logical drives, each with

its own file system which can be mounted by the operating system and treated as an

individual drive.

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• Disk space analyzers for the visualization of disk space usage by getting the size

for each folder (including sub folders) & files in folder or drive. showing the distribution of

the used space.

• Disk storage utilities

o Archive utilities output a stream or a single file when provided with a directory or a

set of files. Archive utilities, unlike archive suites, usually do not include compression or

encryption capabilities. Some archive utilities may even have a separate un-archive utility

for the reverse operation.

o File managers provide a convenient method of performing routine data

management tasks, such as deleting, renaming, cataloging, uncataloging, moving,

copying, merging, generating and modifying data sets.

o Cryptographic utilities encrypt and decrypt streams and files.

o Hex editors (or binary file editor or byte editor) is a type of computer program that

allows a user to manipulate the fundamental binary (0 / 1, zero / one) data that makes up

computer files. The name 'hex' comes from the fact that hexadecimal is the standard

numerical format for digital data on a screen when editing at this level. Note that computer

files can be very small (just a name, with no content) to very large (content spanning

multiple hard disks). A typical computer file occupies multiple areas on the platter(s) of a

disk drive, whose contents are put together to form the file. Hex editors that were designed

to read ("parse") and edit sector data from the physical segments of floppy or hard disks

were sometimes called sector editors or disk editors.

o Memory testers check for memory failures.

• Network utilities analyze the computer's network connectivity, configure network

settings, check data transfer or log events.

• Registry cleaners clean and optimize the Windows registry by removing old

registry keys that are no longer in use.

• Screensavers were desired to prevent phosphor burn-in on CRT and plasma

computer monitors by blanking the screen or filling it with moving images or patterns when

the computer is not in use. Contemporary screensavers are used primarily for

entertainment or security.

• System monitors for monitoring resources and performance in a computer system.

• System profilers provide detailed information about the software installed and

hardware attached to the computer.

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c. Name FIVE preliminary Installation Checks that one needs to do before embarking on

installing windows Xp. (6 Marks)

i) You have the Windows XP CD.

ii) You have the product key available. The product key is located on your Windows XP

CD case and is required to install and activate Windows XP.

iii) Your computer hardware is set up. At a minimum, you should connect your keyboard,

mouse, monitor, and CD drive.

iv) You have Windows XP drivers available. Drivers are software that Windows XP uses

to communicate with your computer’s hardware. Most new computers include a CD

containing drivers. If you do not have drivers available, Windows XP may already

include drivers for your hardware. If not, you should be able to download them from

your hardware manufacturer’s Web site after you set up Windows XP.

v) If you are reinstalling Windows XP on an existing computer, you need a backup copy

of your files and settings. The installation process will delete all of your files.

d. Define Windows Registry. (2 Marks)

A simple, hierarchical database of information that Windows operating systems (and some

applications) use to define the configuration of the system.

e. In a computer system, what is a device driver? (2 Marks)

Piece of software that works in conjunction with the operating system and whose function is to

allow the op sys to recognize a new device.

SECTION B: ANSWER ANY THREE QUESTIONS {20 MARKS EACH}.

QUESTION 2

a. List and explain five responsibilities of a computer support staff ( 10 marks)

Support users

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Most users in any computer system are not specialists/techs and since most businesses rely on computer

systems to manage their information, the system support staff will be necessary to offer the users technical

support

Train Users

System support staff are supposed to train users on the computer basics. Since most users are challenged

as far as IT is concerned, some even have a phobia for computers, a system support staff is supposed to

train the users slowly and gradually they appreciate that IT is a complement to their work than an obstacle.

Ensure the system is running

The System Support staff will ensure that all that needs to be done is done so that the system is available

and functioning well at all times. Down time should be minimised. Business should never be interrupted by

systems failure

Conduct routine maintenance

It is necessary to do routine clean up of the applications, operating system and the hardware, just to reduce

on system down time. The maintenance also includes the system and data backups. This provides for

business continuity in case of any emergency.

Management Advisor

Systems Support staff can also suggest/advise ways of enhancing the current systems. Business world is

very dynamic and systems much adapt so as to support business appropriately. This means that the

support staff must be very up to date with current trends in the IT industry and suggest ways of utilising

computer systems so as to support the business objectives and giving it a CA

b. Outline FOUR steps that one can follow to create a new Remote connection (10 Marks)

i. Open Remote Desktop Connection.

ii. In Computer, type a computer name or IP address. The computer can be a terminal server or it

can be a computer running Windows Professional or Server that has Remote Desktop enabled

and for which you have Remote Desktop permissions.

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iii. Click Connect.

The Log On to Windows dialog box appears.

iv. In the Log On to Windows dialog box, type your user name, password, and domain (if

required), and then click OK.

QUESTION 3

a. Outline the main benefits of implementing an effective help desk (10 Marks)

Reducing costs by ensuring efficient allocation of resources.

Better customer care, leading to greater satisfaction and loyalty.

Opening up new business opportunities.

Centralizing of processes improving communication and information management.

Proactive service support.

b. Outline the major steps in software troubleshooting (10 Marks)

1. Close all open programs and dialog windows.

2. Restart the program and try to re-create the problem.

3. If the problem recurs, turn off the computer, let it rest for ten seconds and turn it on again.

4. Log on and try to re-create the problem.

5. If the problem recurs, did you change any configuration settings recently? If so, reverse the

changes.

6. Did you install new hardware or software recently? Uninstall and try to re-create the problem.

7. If the problem recurs, record the exact sequence of actions and clicks that generated the

unexpected results. Also describe in detail how the program reacted and why that reaction was

abnormal or undesirable.

8. Finally, write down word for word the text of any error messages that you see.

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9. Also write down the name of the computer that’s experiencing the problem. On most Windows

machines, go to Start -> Run, and type in sysdm.cpl. Click on the Computer Name tab. Write down

the full name of the computer.

10. Contact tech support.

QUESTION 4

a. Explain in detail FOUR benefits of Remote desktop (10 Marks)

a. Remote desktop access makes data and applications on your home or business

desktop computer available from a laptop or other internet-connected computer

located elsewhere.

b. An advantage of remote desktop access is that you don’t have to spend time copying

data to disks, a pen-drive, or CD-RWs to bring with you, and there isn’t the potential

that you will forget to copy an important file. Your home or business computer’s hard

drive is also less likely to fail than some types of removable media.

c. In addition to copying data to removable media and bringing it with you, other options

include using an “online desktop” or a online file storage service. An online desktop

service lets you access a variety of browser-based programs and store data to a

remote hard drive on the service’s server, while an online file storage service enables

you to upload files to its server and access them from any internet connection.

d. One of the better options for bringing large amounts of data with you is a USB pen-

drive; it is very compact, and most have capacities of 64MB-8GB and can be used with

new and relatively new computers. A portable Zip drive and one or more Zip disks can

also hold a large amount of data and be used with a wider variety of computers.

Standard 3.5″ disks can hold more than many people believe, including fairly long

PowerPoint presentations and large numbers of documents.

e. Overall, using remote desktop access is a good choice if you need to access both data

and specific applications on another computer, but other less expensive options with

fewer technical requirements shouldn’t be overlooked.

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Outline the NTFS (New Technology File System) features (10 Marks)

1. Alternate data streams (ADS) - Alternate data streams allow files to be associated with more than

one data stream. For example, a file such as text.txt can have an ADS with the name of text.txt:secret (of

form filename:streamname) that can only be accessed by knowing the ADS name or by specialized

directory browsing programs. Alternate streams are not detectable in the original file's size but are lost

when the original file (i.e. text.txt) is deleted with a RemoveFile or RemoveFileTransacted call (or a call that

uses those calls), or when the file is copied or moved to a partition that doesn't support ADS (e.g. a FAT

partition, a floppy disk, or a network share). While ADS is a useful feature, it can also easily eat up hard

disk space if unknown either through being forgotten or not being detected.

2. Quotas - Disk quotas were introduced in NTFS v3. They allow the administrator of a computer that

runs a version of Windows that supports NTFS to set a threshold of disk space that users may utilize. It

also allows administrators to keep track of how much disk space each user is using. An administrator may

specify a certain level of disk space that a user may use before they receive a warning, and then deny

access to the user once they hit their upper limit of space. Disk quotas do not take into account NTFS's

transparent file-compression, should this be enabled. Applications that query the amount of free space will

also see the amount of free space left to the user who has a quota applied to them.

3. Sparse files - Sparse files are files which contain sparse data sets, data mostly filled with zeroes.

Many scientific applications can generate very large sparse data sets. Because of this, Microsoft has

implemented support for sparse files by allowing an application to specify regions of empty (zero) data. An

application that reads a sparse file reads it in the normal manner with the file system calculating what data

should be returned based upon the file offset. As with compressed files, the actual size of sparse files are

not taken into account when determining quota limits.

4. Reparse points - This feature was introduced in NTFS v3. These are used by associating a reparse

tag in the user space attribute of a file or directory. When the object manager (see Windows NT line

executive) parses a file system name lookup and encounters a reparse attribute, it knows to reparse the

name lookup, passing the user controlled reparse data to every file system filter driver that is loaded into

Windows 2000. Each filter driver examines the reparse data to see if it is associated with that reparse point,

and if that filter driver determines a match then it intercepts the file system call and executes its special

functionality. Reparse points are used to implement Volume Mount Points, Directory Junctions, Hierarchical

Storage Management, Native Structured Storage and Single Instance Storage.

5. Volume mount points - Similar to Unix mount points, where the root of another file system is

attached to a directory. In NTFS, this allows additional file systems to be mounted without requiring a

separate drive letter (like C: or D:) for each.

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6. Directory Junctions - Similar to Volume Mount Points, however directory junctions reference other

directories in the file system instead of other volumes. For instance, the directory C:\exampledir with a

directory junction attribute that contains a link to D:\linkeddir will automatically refer to the directory D:\

linkeddir when it is accessed by a user-mode application. This function is conceptually similar to symbolic

links to directories in Unix except that the target in NTFS must always be another directory. (Typical Unix

file systems allow the target of a symbolic link to be any type of file.)

7. Hard links - Originally included to support the POSIX subsystem in Windows NT, hard links are

similar to directory junctions, but used for files instead of directories. Hard links can only be applied to files

on the same volume since an additional filename record is added to the file's MFT record. Short (8.3)

filenames are also implemented as additional filename records that don't have separate directory entries.

8. Hierarchical Storage Management (HSM) - Hierarchical Storage Management is a means of

transferring files that are not used for some period of time to less expensive storage media. When the file is

next accessed the reparse point on that file determines that it is needed and retrieves it from storage.

9. Native Structured Storage (NSS) - NSS was an ActiveX document storage technology that has

since been discontinued by Microsoft. It allowed ActiveX Documents to be stored in the same multi-stream

format that ActiveX uses internally. An NSS file system filter was loaded and used to process the multiple

streams transparently to the application, and when the file was transferred to a non-NTFS formatted disk

volume it would also transfer the multiple streams into a single stream.

10. Volume Shadow Copy - The Volume Shadow Copy (VSC) service keeps historical versions of files

and folders on NTFS volumes by copying old, newly-overwritten data to shadow copy (copy-on-write). The

old file data is overlaid on the new when the user requests a revert to an earlier version. This also allows

data backup programs to archive files currently in use by the file system. On heavily loaded systems,

Microsoft recommends setting up a shadow copy volume on separate disk to reduce the I/O load on the

main volume.

11. File compression - NTFS can compress files using a variant of the LZ77 algorithm (also used in the

popular ZIP file format). Although read-write access to compressed files is transparent, Microsoft

recommends avoiding compression on server systems and/or network shares holding roaming profiles

because it puts a considerable load on the processor.

Single-user systems with limited hard disk space will probably use NTFS compression successfully.[citation

needed] The slowest link in a notebook is not the CPU but the speed of the hard drive, so NTFS

compression allows the limited, slow storage space to be better used, in terms of both space and (often)

speed. NTFS compression can also serve as a replacement for sparse files when a program (e.g. a

download manager) is not able to create files without content as sparse files.

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12. Single Instance Storage (SIS) - When there are several directories that have different, but similar,

files, some of these files may have identical content. Single instance storage allows identical files to be

merged to one file and create references to that merged file. SIS consists of a file system filter that

manages copies, modification and merges to files; and a user space service (or groveler) that searches for

files that are identical and need merging. SIS was mainly designed for remote installation servers as these

may have multiple installation images that contain many identical files; SIS allows these to be consolidated

but, unlike for example hard links, each file remains distinct; changes to one copy of a file will leave others

unaltered. This is similar to copy-on-write, which is a technique by which memory copying is not really done

until one copy is modified.

13. Encrypting File System (EFS) - EFS provides strong and user-transparent encryption of any file or

folder on an NTFS volume. EFS works in conjunction with th EFS service, Microsoft's CryptoAPI and the

EFS File System Run-Time Library (FSRTL).

EFS works by encrypting a file with a bulk symmetric key (also known as the File Encryption Key, or FEK),

which is used because it takes a relatively smaller amount of time to encrypt and decrypt large amounts of

data than if an asymmetric key cipher is used. The symmetric key that is used to encrypt the file is then

encrypted with a public key that is associated with the user who encrypted the file, and this encrypted data

is stored in an alternate data stream of the encrypted file. To decrypt the file, the file system uses the

private key of the user to decrypt the symmetric key that is stored in the file header. It then uses the

symmetric key to decrypt the file. Because this is done at the file system level, it is transparent to the user.

Also, in case of a user losing access to their key, support for recovery agents that can unencrypt files has

been built in to the EFS system.

14. Symbolic links - Symbolic links were originally used to support the POSIX subsystem in Windows

NT.[citation needed] Symbolic links (or Soft links) are resolved on the client side. So when a symbolic link is

shared, the target is subject to the access restrictions on the client, and not the server.

15. Transactional NTFS - As of Windows Vista, applications can use Transactional NTFS to group

changes to files together into a transaction. The transaction will guarantee that all changes happen, or none

of them do, and it will guarantee that applications outside the transaction will not see the changes until the

precise instant they're committed.

QUESTION 5

a. Discuss any FIVE tools that can be used to recover from disasters in Windows XP. (10 Marks)

Last Known good configuration

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This is a tool used to recover from registry changes and damage to system files that prevents

windows XP from booting fully. It restores the operating system to the last configuration in

which it booted fully.

Device driver roll back

This is used when installing a new device driver makes the computer unstable. Using this, the

user can revert to the drivers that the device was previously using.

System Restore

This is a recovery tool designed for recovery from problems such as configuration problems,

system instability and installation of software that fails to work. It automatically creates restore

points that can be used to restore the computer to a specific configuration after the computer

encounters some problems. System restore keeps these restore points for 90 days before

deleting them

Uninstalling and reinstalling applications

If an application makes the system unstable, uninstalling it may solve the problem. The

application can then be reinstalled again if its files had been corrupted.

System Configuration Utility and Clean boot

It is a tool for modifying the configuration used to boot the computer. It overcomes boot and

startup problems when the problem is not so serious as to prevent Windows XP from booting

and the user from logging on.

Recovery Console

This is a command-line tool for fixing configuration problems when windows XP cannot boot

fully and the last known good configuration cannot solve the problem. It can be used to perform

many tasks without starting Windows XP, e.g. starting and stopping services, reading and

writing information on a disk, and formatting drives. However, it should only be used by

advanced users.

Parallel installation

If recovery console does not solve the problem, a parallel installation of Windows XP can be

performed. Once the new installation is booted, it can be used to repair the main installation.

Automatic system Recovery

This should be the last resort after all the other recovery tools have failed. It is the last step

before reinstalling Windows XP. It backs up the contents of the system volume to a large

archive file and saves a small amount of vital configuration information to a floppy disk. When a

problem that can not be solved using other recovery tools occurs, one can boot from the

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Window XP CD to a special ASR mode. The floppy disk is then supplied and Windows XP can

be guided on where find the ASR backup.

Reinstallation

If all other recovery methods have failed and ASR has failed, one would have to reinstall

Windows XP to recover from the problem encountered.

b. Discuss FIVE advantages of using a centralized system registry. (10 Marks)

Advantages

i) The Windows centralized Registry has a number of advantages over legacy INI files:

ii) Strongly-typed data can be stored in the Registry, as opposed to only textual information in

INI files.

iii) Separation of machine configuration from user configuration. When a user logs into a

Windows NT/2000/XP/Server 2003 computer, the user-based registry settings are loaded

from a user-specific path rather than from a read-only system location. This allows multiple

users to share the same machine, and also allows programs to work for a least-privilege

user.

iv) Group Policy allows administrators on a Windows-based computer network to centrally

manage program and policy settings. Part of this involves being able to set what an entry

in the registry will be for all the computers on the network, and affect nearly any installed

program — something almost impossible with per-program configuration files each with

custom layouts, stored in dispersed locations.

v) Standardization of the method of storing configuration data across diverse applications.

vi) The registry can be accessed over a network connection for remote management/support,

including from scripts, using the standard set of APIs, as long as the Remote Registry

service is running and firewall rules permit this.

vii) The entire registry can be backed up more easily as it is just a small number of files in

specific locations. However, it is much harder to back up and restore configuration of a

specific application.

viii) Since accessing the registry does not require parsing, it can be read from and written to

more quickly than a text file can be. However, the registry becomes a large file to process

once per boot.

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ix) Portions of settings like any subset of an application configuration can be saved in a text-

based .REG file, which can be edited with any text editor later. .REG files can easily be

merged back into the registry both by unattended batch file or by the user just double-

clicking on the file without harming any setting that is not explicitly stated in the .REG file.

This is very useful for administrators and support personnel who want to pre-set or pre-

configure only a few options like approving the EULA of a certain application.

x) The registry is constructed as a database, and offers DB-like features such as atomic

updates. If two processes attempt to update the same registry value at the same time, one

process's change will precede the other's, so one will only last a short time until the second

gets written. With changes in a file system, such race conditions can result in interleaved

data that doesn't match either attempted update. Windows Vista provides transactional

updates to the registry, so the atomicity guarantees can be extended across multiple key

and/or value changes, with traditional commit-abort semantics. (Note that NTFS provides

such support for the file system as well, so the same guarantees could be obtained with

traditional configuration files.)

End of Exam

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