Module 3: Operating Systems Flashcards
Operating System
Manages the computer’s resources and lets us interact with it
Two main parts of an operating system
- Kernel: Process Manager, Memory Manager, File manager, I/O Manager
- User Space: Applications
What is a Kernel
Main core of OS, talks to hardware and manages system resources.
As Users we don’t interact directly with the Kernel, instead we interact with the user space
What is the User Space?
Everything outside of the Kernel, like system programs, applications, User Interfaces etc.
Most Common OS
Windows
Mac OS
Linux
3 Components to handling Files in an OS
- Data
- Metadata
- File System
Major File system Used for Windows
NTFS
Major File system for Linux
Different distributions have different file systems, but a major one for Linux is EXT4
Block Storage
A method of data storage that improves faster handling of data because the data isn’t stored as one long piece and can be accessed quicker
File Metadata
Provides information ABOUT the file, such as file type or extension, owner, last edited, size, etc.
Process
A program that is executing, like our internet browser or text editor
Program
An application that can be run.
Program vs Process
We can run many processes of the same program at the same time, but you can only have one program.
Like opening multiple chrome tabs at the same time.
How does a Kernel run a program?
The Kernel starts a process, assigns memory and CPU resources to that process and schedules time for it to run. The CPU then executes the process during it’s allocated time slice. The Kernel also manages how processes are terminated
Time Slice
A very short interval of time that get’s allocated to a process for CPU execution.
Virtual Memory
The combination of hard drive space and RAM that acts like memory that our processes can use.
How is memory allocated to processes when the process is created?
Chunks of data, called pages, are taken from the program.
The pages are then stored in virtual memory
The pages are then sent to the Physical Memory to be read
How does the Kernel manage I/O devices?
The Kernel loads up drivers that allows for the communication with the device, as well as manages the transfer of data in and out of the devices
Potential Hardware sources of “slow” computer
- Not enough CPU to execute processes
- Not enough Ram to load processes
- Too much input or output from devices
What are the two ways that user’s can interact with the OS?
- Shell
- GUI
The Boot Process
- Powered on
- Bios/UEFI initializes the hardware by running a POST TEST
- Boot Device is selected
- Searches for a Boot Loader
- Uses Bootloader to start OS
- Kernel Gets Loaded
- Essential System Processes and User Space items are launched
