Chapter 3-Hardware Flashcards
What in relation to RAM can cause a system crash
When the amount of RAM is exceeded due to multiple programs running
What is the basis behind virtual memory
That if a system crash is caused due to the amount of available RAM being exceeded through multiple programs running, it can be solved by using the HDD or SSD.
What is virtual memory
Memory management system that makes use of secondary storage and software to enable a computer to compensate for the shortage of actual physical RAM memory. It is RAM storage+swap space on hard disk or SSD
Very basic: how is a program executed
Data is loaded into memory from HDD/SSD when required
What are Utility programs(utilities)
Part of the Operating system which carries out certain functions such as virus checking, defragmentation and screensaver
How does the size of RAM affect the CPU/how is increasing it a benefit
The larger the RAM the faster the CPU can operate
What is disk thrashing
Problem in a hard disk drive caused by excessive swapping in and out of data causing a high rate of read/write head movements during vital memory operations
What are the main benefits of virtual memory (3)
It reduces the need to buy and install more (expensive) RAM, but accessing data from virtual memory is slower than physical.
No need to waste space on data that is not being used (Eg. During error handling)
Programs larger than physical memory can still be executed
What is thrash point
Point at which the execution of a program comes to a halt because the system is so busy moving data in and out of memory rather than executing the program
What does thrashing lead to
Premature failure of HDD
How can thrashing be reduced (4)
By installing more RAM
Using an SSD instead of an HDD
Reducing the size of a swap file
Reducing the number of programs running at once
What is data redundancy
Unnecessary storing of the same data on several storage devices at the same time. Done in case of maintenance and repair, so that customer can access data at any time
What is cloud storage
Method of data storage where data is stored on remote/offline servers. The physical storage may be on hundreds of servers in many locations
By whom is the physical environment owned and what may it include
A hosting company, may include hundreds of servers in many locations.
Where can a user save their data other than a local HDD or other storage device
In the cloud
What are the 3 common systems in cloud storage
Private cloud
Public cloud
Hybrid cloud
Explain public cloud
Storage environment where customer/client and cloud storage environment provider are different companies
Explain private cloud
Storage provided by dedicated environment behind company firewall. Customer/client and cloud storage provider are integrated and operate as a single entity
Explain hybrid cloud
A combination of the 2 other enviroments. Some data resides in the private cloud, and less sensitive/commercial data can be accessed from a public cloud storage provider
What are the benefits of cloud storage (5)
No need for customer/client to carry external storage device on them or even use the same computer to restore/retrieve information
Almost unlimited storage capacity
Cloud storage will allow recovery of their data if a customer/client has a failure on their hard disk or back-up device
Customer/client files stored can be accessed at anytime anywhere in the world provided there is internet access
Helps alleviate data loss and recovery as it provides the user with remote back-up of data
What are the drawbacks of cloud storage (3)
Costs can be high if large storage capacity is needed and the high down/upload data transfer with the ISP can be expensive
Risk of loss of all backup data if the cloud storage company fails
Would be problems accessing/downloading data/files if there is poor internet connection
Concerns regarding data security when using cloud storage (3)
What physical security exists regarding the building where the data is housed?
How good is the service provider’s resistance to natural disasters and power cuts?
What safeguards exist regarding persons; who work for the company-can they use their authorisation codes to access confidential data for monetary purposes?
NIC
Network Interface Cars
Hardware component (circuit board/chip required to allow a device to connect to a network (internet)
What is a MAC address and what is it make up of
Media Access Control
Unique identifier which acts as a network address for a device. Takes form NN-NN-NN-DD-DD-DD
Manufacturer code=NN - device code =DD
48 bits shown as six groups of hexadecimal digits
Compare NIC to WNIC
They both are used to connect devices to internet/other networks
WNIC uses wireless connectivity, utilising antennas to communicate with networks via microwaves.
NIC normally plugs into USB port/is part of an integrated internal circuit
What is another word for device code and what happens to the MAC if the NIC card is replaced
Serial number
The MAC address will change
What are the 2 types of MAC addresses+short description
LAA-Locally Administered MAC address
UAA-Universally Administered MAC address
-provided by manufacturer at factory
-most common and not normally changed
Why would a MAC address need to be changed using an LAA
Certain software on mainframe systems need all MAC addresses to fall into a strict format (change to suit format)
To bypass a MAC address filter on firewall. Sometimes only certain formats are allowed through, others will be blocked
To get past certain types of network restrictions. May need to emulate unrestricted MAC addresses
What do protocols do
They define the rules that must be agreed by senders and receivers of data communicating through the internet
Describe public and private IP addresses
When a device connects to the internet, it is assigned a unique public address, all the devices on the network will have the same public address, but different private ones on the network
When a device connects to a private network, it is assigned a private IP address but the router, this is unique on the network, but may be used on a separate network
IPv4 vs IPv6
IPv4 is based on 32 bits and is written as 4 groups of 8 bits in denary format, it only being 32 bits significantly reduces the amount of potential devices+routers on the internet
IPv6 is based on 18-bit presented in 8 groups of HEXADECIMAL NUMBERS and use colons
Designed after IPv4 to allow internet to grow in terms of the number of hosts+potential increase in amount of data traffic
What are the advantages of using IPv6 (3)
It removes the risk of IP address collisions
Has built in authentication checks
Allows for more efficient package routes
What is + General features of system software (3)
Set of programs to control and manage the operation of computer hardware
Provides platform on which other software can run
provides human computer interface (HCI)
Controls allocation and usage of hardware resources
What are what are examples of application software (4)
Used to perform various apps on computer
Allows a user to perform specific tasks in computers resources
May be single(notes) or suite (Microsoft office) of programs
user can execute software as and when they require
What utilities are usually offered by computer software systems (6)
Back-up software
File compression and management
Virus checkers
Defragmentation software
Security
Disk contents analysis and repair
Where do virus checkers run and why should they be kept up to date
They run in the backyard and need to be kept up to date to maintain the ability to guard against being infected by malware
Malware
Programs (viruses, Trojan-horse and worms) that are installed on a computer with the aim of deleting, corrupting or manipulating data illegally
What does anti virus check do (6)
It compares a possible virus against a data base of known viruses
Check software/files before they are loaded onto the computer
Carry out heuristic checking
Put infected files into quarantine
Needs to be kept up to date (new virus discovery)
Full system checks once a week- dormant viruses
How can you prevent viruses
Be careful when downloading material from internet
Not opening files/websites emailed by unknown senders
Not using non-original software
Anti virus software
What is quarantine/what does it do
To isolate a file(to delete) identified by anti-virus checker as being infected
Allows virus to be automatically detected
Allows user to make decision about deletion (maybe it was a false positive)
Defragmentation
Process that réorganisés sectors on an HDD by rearranging blocks of data until they are contiguous which reduces the read/write head movements.
Conséquence of HDD becoming full
Slower data access time as the read-write head will now require several moments to find+retrieve the data to make up the required file from the different sectors and tracks on the disks surface
What rearranges blocks of data to store files in contiguous sectors
What does it allow
Disk defragmenter
Faster data access and retrieval as there are fewer read-write head movements to access the files
What does a backup utility do
Allow a schedule for backing up files to be made
Only carries out backup procedures once there has been change to a file
How many, and what versions of a file should there be for total security
- Current one stored in internal HDD/SSD
- Locally backed up (local SSC)
- remote backup version (iCloud )
What is security software and what does it do (4)
Over arching utility that
Manages access control over user accounts( ID checks and passwords)
Protects network interfaces (firewall)
Uses encryption and decryption to secure intercepted data
Oversees updating of software (is request from legit source)
Screensaver
Software that suppplies a still or moving image on a monitor if a computer has been inactive for a long time. Initially used to protects CRT monitors from phosphor burn
Provides extra security and is used when doing virus scans and distributed computing applications
Device driver
Software that
Communicates with OS to translate data into format understood by hardware peripheral device
Would not work without
“Device not registered”
Descriptor
Collection of info about device plugged into USB port
Can be vendor ID (VID) or product ID (PID) or serial number
What does it mean if a language is portable
It can be used on more than 1 device without having to be redone
Disadvantage to programmer.of using high level instead of low level language
The time it takes for translation
Firmware
Computer software that gives you low level control. But it forms part of hardware. Inside ROM.
REDO
Where is BIOS stored
EEPROM
Electrically Erasable Programmable Read Only Memory
