22 min read

File, Device and Security Management

File systems and paths, drivers and spooling, and how the OS protects users and data.

File Management

The OS stores files using a file system — a way of organising data on a drive and recording where each file is. It keeps each file's name, size, type, dates, location and permissions .

Files live in folders (directories) arranged like a tree. A path says exactly where a file is:Windows: C:\Users\Ravi\Documents\invoice-042.xlsx — a drive letter, then folders separated by backslashes.Linux and macOS: /home/ravi/documents/invoice-042.xlsx — everything starts from the root /, separated by forward slashes.An absolute path starts from the drive or root. A relative path starts from the folder you are in now. You will use both in the command-line lessons.

The OS also handles slow devices with a buffer or a queue . Spooling stores print jobs on the disk and sends them to the printer one after another, so users can carry on working instead of waiting. Plug and play means the OS recognises a new device and loads its driver automatically.

How the OS protects the system
How the OS protects the system

Worked example

Permissions on Hillside Print House's server

Folder Designers Accounts Counter staff Customer designs Read and write No access Read only Accounts No access Read and write No access Price lists Read only Read and write Read only Each person only has the access their job needs. This is called the principle of least privilege .

Practice

A new scanner does not work until software from the maker is installed. What is that software?

File Management

The OS stores files using a file system — a way of organising data on a drive and recording where each file is. It keeps each file's name, size, type, dates, location and permissions .

Folders and Paths

Files live in folders (directories) arranged like a tree. A path says exactly where a file is:Windows: C:\Users\Ravi\Documents\invoice-042.xlsx — a drive letter, then folders separated by backslashes.Linux and macOS: /home/ravi/documents/invoice-042.xlsx — everything starts from the root /, separated by forward slashes.An absolute path starts from the drive or root. A relative path starts from the folder you are in now. You will use both in the command-line lessons.

Device Management

The OS also handles slow devices with a buffer or a queue . Spooling stores print jobs on the disk and sends them to the printer one after another, so users can carry on working instead of waiting. Plug and play means the OS recognises a new device and loads its driver automatically.

Security Management

How the OS protects the system
How the OS protects the system

Worked example

Permissions on Hillside Print House's server

Folder Designers Accounts Counter staff Customer designs Read and write No access Read only Accounts No access Read and write No access Price lists Read only Read and write Read only Each person only has the access their job needs. This is called the principle of least privilege .

Practice

A new scanner does not work until software from the maker is installed. What is that software?

Folder	Designers	Accounts	Counter staff
Customer designs	Read and write	No access	Read only
Accounts	No access	Read and write	No access
Price lists	Read only	Read and write	Read only