STUDY GUIDE · GKU 5
Platform technologies: the operating system study guide (Information Technology)
Every service an IT specialist runs sits on an operating system, and most of the hard days are spent on that layer: a server that will not boot, a disk that fills at night, a service that starts and stops, a machine that is slow for no visible reason. This unit covers the platform itself. It compares Windows and Unix-class systems — installation, users and groups, permissions, services, packages and updates — and then the mechanisms underneath: how processes and threads are represented and scheduled, how virtual memory turns each process's addresses into physical frames through page tables and a TLB, how files, directories, inodes, mounts and I/O requests are organised, and how to diagnose the failures that reach a help desk. Every section opens with a quick-revision card; the scheduling, paging and file examples show every step of the calculation.
Structured by the official ETEC subject standard for this topic: every listed topic and learning outcome, with formulas, figures and worked examples. The full sections are available to members in the app.
SKU 5.1 · Operating systems
Windows and Unix-class systems: installation, configuration and use
The two families an IT team supports, how each is installed and licensed, where its settings and logs live, how users, groups, permissions, services and packages are managed, and how the same administrative job is done on each side.
Processes, threads and CPU scheduling
What a process is and what the operating system keeps about it, the five process states, how a context switch works, what a thread shares and what it owns, and how FCFS, SJF, priority and round-robin scheduling choose the next process — with the metrics that compare them.
Memory management and virtual memory
Why each process gets its own address space, how partitioning and paging divide physical memory, how a logical address becomes a frame through the page table and the TLB, what a page fault costs, and how replacement policies and thrashing decide whether the machine stays fast.
File and I/O systems
How files, directories, inodes and mounts are organised, how permissions decide who may read or write, how the file system maps a byte offset to a disk block, and how buffering, caching and disk scheduling turn many small requests into a workable stream.
Operating-system troubleshooting
A method for the failures an IT team meets most: the machine will not boot, a service will not start, the system is slow, or the disk is full — with the Windows and Linux tools that show what is happening and the order in which to use them.
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