Section: Information System Operations, Maintenance and Support

Section: Information System Operations, Maintenance and Support
Explanation
Explanation/Reference:
Supercomputers are very large and expensive computers with the highest processing speed, designed to
be used for specialized purpose or fields that require extensive processing power.
A supercomputer is focused on performing tasks involving intense numerical calculations such as weather
forecasting, fluid dynamics, nuclear simulations, theoretical astrophysics, and complex scientific
computations.
A supercomputer is a computer that is at the frontline of current processing capacity, particularly speed of
calculation. The term supercomputer itself is rather fluid, and the speed of today's supercomputers tends to
become typical of tomorrow's ordinary computer. Supercomputer processing speeds are measured in
floating point operations per second, or FLOPS.
An example of a floating point operation is the calculation of mathematical equations in real numbers. In
terms of computational capability, memory size and speed, I/O technology, and topological issues such as
bandwidth and latency, supercomputers are the most powerful, are very expensive, and not cost-effective
just to perform batch or transaction processing. Transaction processing is handled by less powerful
computers such as server computers or mainframes.
For your exam you should know the information below:
Common Types of computers
Supercomputers
A supercomputer is focused on performing tasks involving intense numerical calculations such as weather
forecasting, fluid dynamics, nuclear simulations, theoretical astrophysics, and complex scientific
computations. A supercomputer is a computer that is at the frontline of current processing capacity,
particularly speed of calculation. The term supercomputer itself is rather fluid, and the speed of today's
supercomputers tends to become typical of tomorrow's ordinary computer. Supercomputer processing
speeds are measured in floating point operations per second, or FLOPS. An example of a floating point
operation is the calculation of mathematical equations in real numbers. In terms of computational
capability, memory size and speed, I/O technology, and topological issues such as bandwidth and latency,
supercomputers are the most powerful, are very expensive, and not cost-effective just to perform batch or
transaction processing. Transaction processing is handled by less powerful computers such as server
computers or mainframes.
Mainframes
The term mainframe computer was created to distinguish the traditional, large, institutional computer
intended to service multiple users from the smaller, single user machines. These computers are capable of
handling and processing very large amounts of data quickly. Mainframe computers are used in large
institutions such as government, banks and large corporations. They are measured in MIPS (million
instructions per second) and respond to up to 100s of millions of users at a time.
Mid-range servers
Midrange systems are primarily high-end network servers and other types of servers that can handle the
large-scale processing of many business applications. Although not as powerful as mainframe computers,
they are less costly to buy, operate, and maintain than mainframe systems and thus meet the computing
needs of many organizations. Midrange systems have become popular as powerful network servers to help
manage large Internet Web sites, corporate intranets and extranets, and other networks. Today, midrange
systems include servers used in industrial process-control and manufacturing plants and play major roles in
computer-aided manufacturing (CAM). They can also take the form of powerful technical workstations for
computer-aided design (CAD) and other computation and graphics-intensive applications. Midrange system
are also used as front-end servers to assist mainframe computers in telecommunications processing and
network management.
Personal computers
A personal computer (PC) is a general-purpose computer, whose size, capabilities and original sale price
makes it useful for individuals, and which is intended to be operated directly by an end-user with no
intervening computer operator. This contrasted with the batch processing or time-sharing models which
allowed larger, more expensive minicomputer and mainframe systems to be used by many people, usually
at the same time. Large data processing systems require a full-time staff to operate efficiently.
Laptop computers
A laptop is a portable personal computer with a clamshell form factor, suitable for mobile use.[1] They are
also sometimes called notebook computers or notebooks. Laptops are commonly used in a variety of
settings, including work, education, and personal multimedia.
A laptop combines the components and inputs as a desktop computer; including display, speakers,
keyboard, and pointing device (such as a touchpad), into a single device. Most modern-day laptop
computers also have a webcam and a mice (microphone) pre-installed. [citation needed] A laptop can be
powered either from a rechargeable battery, or by mains electricity via an AC adapter. Laptops are a
diverse category of devices, and other more specific terms, such as ultra-books or net books, refer to
specialist types of laptop which have been optimized for certain uses. Hardware specifications change
vastly between these classifications, forgoing greater and greater degrees of processing power to reduce
heat emissions.
Smartphone, tablets and other handheld devices
A mobile device (also known as a handheld computer or simply handheld) is a small, handheld computing
device, typically having a display screen with touch input and/or a miniature keyboard.
A handheld computing device has an operating system (OS), and can run various types of application
software, known as apps. Most handheld devices can also be equipped with Wi-Fi, Bluetooth, and GPS
capabilities that can allow connections to the Internet and other Bluetooth-capable devices, such as an
automobile or a microphone headset. A camera or media player feature for video or music files can also be
typically found on these devices along with a stable battery power source such as a lithium battery.
Early pocket-sized devices were joined in the late 2000s by larger but otherwise similar tablet computers.
Much like in a personal digital assistant (PDA), the input and output of modern mobile devices are often
combined into a touch-screen interface.
Smartphone's and PDAs are popular amongst those who wish to use some of the powers of a conventional
computer in environments where carrying one would not be practical. Enterprise digital assistants can
further extend the available functionality for the business user by offering integrated data capture devices
like barcode, RFID and smart card readers.
Thin Client computers
A thin client (sometimes also called a lean, zero or slim client) is a computer or a computer program that
depends heavily on some other computer (its server) to fulfill its computational roles. This is different from
the traditional fat client, which is a computer designed to take on these roles by itself. The specific roles
assumed by the server may vary, from providing data persistence (for example, for diskless nodes) to
actual information processing on the client's behalf.
The following answers are incorrect:
Mid-range servers- Midrange systems are primarily high-end network servers and other types of servers
that can handle the large-scale processing of many business applications. Although not as powerful as
mainframe computers, they are less costly to buy, operate, and maintain than mainframe systems and thus
meet the computing needs of many organizations. Midrange systems have become popular as powerful
network servers to help manage large Internet Web sites, corporate intranets and extranets, and other
networks. Today, midrange systems include servers used in industrial process-control and manufacturing
plants and play major roles in computer-aided manufacturing (CAM).
Personal computers - A personal computer (PC) is a general-purpose computer, whose size, capabilities
and original sale price makes it useful for individuals, and which is intended to be operated directly by an
end-user with no intervening computer operator. This contrasted with the batch processing or time-sharing
models which allowed larger, more expensive minicomputer and mainframe systems to be used by many
people, usually at the same time. Large data processing systems require a full-time staff to operate
efficiently.
Thin Client computers- A thin client (sometimes also called a lean, zero or slim client) is a computer or a
computer program that depends heavily on some other computer (its server) to fulfill its computational
roles. This is different from the traditional fat client, which is a computer designed to take on these roles by
itself. The specific roles assumed by the server may vary, from providing data persistence (for example, for
diskless nodes) to actual information processing on the client's behalf.
The following reference(s) were/was used to create this question:
CISA review manual 2014 page number 246
http://en.wikipedia.org/wiki/Thin_client
http://en.wikipedia.org/wiki/Mobile_device
http://en.wikipedia.org/wiki/Personal_computer
http://en.wikipedia.org/wiki/Classes_of_computers
http://en.wikipedia.org/wiki/Laptop

Explanation/Reference:
The Work Recovery Time (WRT) determines the maximum tolerable amount of time that is needed to verify the system and/or data integrity. This could be, for example, checking the databases and logs, making sure the applications or services are running and are available. In most cases those tasks are performed by application administrator, database administrator etc. When all systems affected by the disaster are verified and/or recovered, the environment is ready to resume the production again.
For your exam you should know below information about RPO, RTO, WRT and MTD:
Stage 1: Business as usual
Business as usual

Image Reference - http://defaultreasoning.files.wordpress.com/2013/12/bcdr-01.png At this stage all systems are running production and working correctly.
Stage 2: Disaster occurs
Disaster Occurs

Image Reference - http://defaultreasoning.files.wordpress.com/2013/12/bcdr-02.png On a given point in time, disaster occurs and systems needs to be recovered. At this point the Recovery Point Objective (RPO) determines the maximum acceptable amount of data loss measured in time. For example, the maximum tolerable data loss is 15 minutes.
Stage 3: Recovery
Recovery

Image Reference - http://defaultreasoning.files.wordpress.com/2013/12/bcdr-03.png At this stage the system are recovered and back online but not ready for production yet. The Recovery Time Objective (RTO) determines the maximum tolerable amount of time needed to bring all critical systems back online. This covers, for example, restore data from back-up or fix of a failure. In most cases this part is carried out by system administrator, network administrator, storage administrator etc.
Stage 4: Resume Production
Resume Production

Image Reference - http://defaultreasoning.files.wordpress.com/2013/12/bcdr-04.png At this stage all systems are recovered, integrity of the system or data is verified and all critical systems can resume normal operations. The Work Recovery Time (WRT) determines the maximum tolerable amount of time that is needed to verify the system and/or data integrity. This could be, for example, checking the databases and logs, making sure the applications or services are running and are available.
In most cases those tasks are performed by application administrator, database administrator etc. When all systems affected by the disaster are verified and/or recovered, the environment is ready to resume the production again.
MTD

Image Reference - http://defaultreasoning.files.wordpress.com/2013/12/bcdr-05.png The sum of RTO and WRT is defined as the Maximum Tolerable Downtime (MTD) which defines the total amount of time that a business process can be disrupted without causing any unacceptable consequences. This value should be defined by the business management team or someone like CTO, CIO or IT manager.
The following answers are incorrect:
RPO - Recovery Point Objective (RPO) determines the maximum acceptable amount of data loss measured in time. For example, the maximum tolerable data loss is 15 minutes.
RTO - The Recovery Time Objective (RTO) determines the maximum tolerable amount of time needed to bring all critical systems back online. This covers, for example, restore data from back-up or fix of a failure.
In most cases this part is carried out by system administrator, network administrator, storage administrator etc.
MTD - The sum of RTO and WRT is defined as the Maximum Tolerable Downtime (MTD) which defines the total amount of time that a business process can be disrupted without causing any unacceptable consequences. This value should be defined by the business management team or someone like CTO, CIO or IT manager.
The following reference(s) were/was used to create this question:
CISA review manual 2014 page number 284
http://defaultreasoning.com/2013/12/10/rpo-rto-wrt-mtdwth/

Periodically reviewing log files is the most effective way to detect intrusion attempts from outside the organization, as they can provide evidence of unauthorized access attempts, source IP addresses, timestamps and other relevant information. Using smart cards with one-time passwords or installing biometrics-based authentication can prevent unauthorized access, but not detect it. Configuring the router as a firewall can block unwanted traffic, but not log it. References: ISACA, CISA Review Manual, 27th Edition, 2018, page 361