1.5.4 Operating System Managers 2 / Utility Software & Flashcards
File Manager - Access Rights
The file manager is responsible for setting and managing the access rights of each file.
For example, the file manager decides if a file can be:
Read.
Modified.
Executed.
File Manager - Locations
The file manager is responsible for keeping track of where specific files and folders are located in secondary storage.
File Manager - File Types
The file manager is responsible for determining the type of a file, and sending it to the correct application.
Device Management - Purpose of Device Manager
The device manager keeps track of which devices are connected to which ports.
The device manager also allows applications to read or write data to each device.
Device Management - Examples of peripheral devices
Examples of devices that the device manager manages are:
Keyboard.
Mouse.
Printer.
Webcam.
Device Management - Device drivers
The device manager works closely with special system software called device drivers.
Device drivers contain software that tell the operating system how to understand the data coming from the device and what format it expects to receive data in.
User Management - Single-user operating system
A single-user operating system is an OS which supports one user at a time.
A single-user OS may or may not allow multiple user accounts, although only one may use the system at once.
User Management - Multi-user operating system
A multi-user operating system allows several users to be connected at the same time.
User Management - User Manager
A user manager keeps track of which users can access the system and who is currently logged in.
The user manager also handles authentication, or logging in.
The user manager is also responsible for making decisions based on access rights:
For example: Can user X access document Y?
Encryption Software - What is encryption
Encryption is the “scrambling” of data.
It works by applying a special encryption algorithm to the data in the file.
Encryption processes are very mathematical processes. Strong encryption algorithms can be the result of years of professional research.
Encryption Software - Encryption in operating systems
Good encryption utilities will work closely with the operating system to encrypt and decrypt files in real time as you need to access them.
Encryption Software - What is decryption?
Decryption is when an authorized party uses a special key to un-scramble the data.
The key prevents unauthorized users from accessing the data.
Defragmentation Software - Fragmentation
When files are written to secondary storage, they are not always written in one continuous block. They may be split up.
If a single file is stored in different places on a storage device, we say that the file is fragmented.
Fragmented files take longer to load.
Defragmentation Software - Defragmentation
Defragmentation software reorganises the data on the storage device so that data from the same file is stored in adjacent blocks.
Defragmentation software will increase the performance of the computer.
Defragmentation Software - SSD
Solid state drives (SSDs) provide random access to data.
This means that fragmented data does not take any longer to load.
SSDs should never be defragmented because this will push the device towards its read/write cycle limit, which shortens its lifetime.
