MCA-105 Operating Systems with Linux Notes from Unnati Educations cover all 4 units of this GGSIPU MCA Semester 1 paper in 94 pages: 40 sections, 26 worked examples and numericals, 4 C programs, 31 diagrams and 86 exam-style questions. They follow the MCA syllabus applicable from session 2025-26 and come only as a printed book.
Written by Prateek Talwar, Founder, Unnati Educations · Reviewed by Ritik Rawat, B.Tech, Senior Full Stack Developer · Checked against the GGSIPU MCA Scheme of Examination and Detailed Syllabus (AC Sub Committee 1 Aug 2025) · Updated 14 October 2026 · Editorial policy
Scheme: MCA scheme 2025-26 | Applies to: batch admitted 2025-26 onwards (affiliated institutes) | Verified against: MCA Scheme of Examination and Detailed Syllabus, AC Sub Committee 1 Aug 2025
MCA-105 Operating Systems with Linux at a glance: GGSIPU MCA Sem 1 credits, units and exam pattern
| Code and title | MCA-105 Operating Systems with Linux |
|---|---|
| Course and semester | MCA (two years), Semester 1 |
| Type and credits | Theory paper, 3 credits (L 3, T/P 0); 44 hours across units (11, 11, 12, 10) |
| Marks | End-term paper: 60 marks. Internal and end-term split not printed; pass marks stated as 40 out of 100 for every paper. |
| Applies to | Affiliated institutes, academic session 2025-26 onwards |
| End-term pattern | Q1 compulsory, objective or short answers on the whole syllabus, 12 marks; then one of two questions from each unit, 12 marks each (12 + 48 = 60 marks) |
| Units | 4 (the official PDF numbers the units without titles) |
| Paired lab | MCA-163 Operating Systems with Linux Lab, L 0, T/P 2, 1 credit |
Every question maps to one of four course outcomes, from OS structure (CO1) to system calls (CO4). MCA-105 sits with four other theory papers in the GGSIPU MCA Semester 1 papers.
MCA-105 Operating Systems with Linux Notes unit-wise: 26 worked examples and numericals across 4 units
Each unit ends with a Linux section, a quick revision table and exam questions. Unit titles are the notes' own, because the official PDF numbers units only. Notes for every other paper of the course are listed under GGSIPU MCA notes.
MCA-105 Unit 1: OS Concepts, System Calls, Processes, Threads and Linux Basics
Pages 4 to 23, six sections. It explains dual-mode operation and how a system call traps into the kernel, compares five OS types, then covers process states, the PCB, fork(), IPC models and threading models, and closes with Linux architecture and 20 basic commands. Count: 2 solved examples, 1 C program, 8 diagrams, 12 short-answer and 8 long-answer questions.
| Basis | Process | Thread |
|---|---|---|
| Weight | Heavyweight | Lightweight |
| Memory | Own address space | Shares the process's address space |
| Communication | Needs IPC (pipes, shared memory) | Through shared variables |
| Linux call | fork() | pthread_create() / clone() |
Quick look: process vs thread (from page 18)
- Basis
- Weight
- Process
- Heavyweight
- Thread
- Lightweight
- Basis
- Memory
- Process
- Own address space
- Thread
- Shares the process's address space
- Basis
- Communication
- Process
- Needs IPC (pipes, shared memory)
- Thread
- Through shared variables
- Basis
- Linux call
- Process
fork()- Thread
pthread_create()/clone()
MCA-105 Unit 2: Process Synchronization, CPU Scheduling and Linux Processes
Pages 24 to 49, ten sections. Peterson's solution, the Bakery algorithm, semaphores, three classical problems and monitors come first. The scheduling half solves FCFS, SJF, SRTF, priority and Round Robin with Gantt charts, then one five-process question six ways, ending with ps, nice and wait(). Count: 9 worked items, 1 C program with output, 5 diagrams, 12 short-answer and 9 long-answer questions.
| Algorithm | Average TAT (ms) | Average WT (ms) |
|---|---|---|
| FCFS | 7.4 | 4.6 |
| SRTF | 5.8 | 3 |
| Round Robin (q = 2) | 8.6 | 5.8 |
Quick look: one five-process data set, three algorithms (from page 44)
- Algorithm
- FCFS
- Average TAT (ms)
- 7.4
- Average WT (ms)
- 4.6
- Algorithm
- SRTF
- Average TAT (ms)
- 5.8
- Average WT (ms)
- 3
- Algorithm
- Round Robin (q = 2)
- Average TAT (ms)
- 8.6
- Average WT (ms)
- 5.8
MCA-105 Unit 3: Deadlocks, Memory Management and Virtual Memory
Pages 50 to 72, twelve sections and the most calculation-heavy unit: resource-allocation graphs, prevention, the Banker's safety and request algorithms, detection and recovery. Memory runs from first, best and worst fit through paging, segmentation, demand paging and thrashing, ending with mmap(). Count: 10 worked items, 1 C program with output, 9 diagrams, 12 short-answer and 10 long-answer questions.
| Algorithm | Page faults | Hit ratio |
|---|---|---|
| FIFO | 15 | 25% |
| Optimal | 9 | 55% |
| LRU | 12 | 40% |
Quick look: page faults on one reference string with 3 frames (from page 66)
- Algorithm
- FIFO
- Page faults
- 15
- Hit ratio
- 25%
- Algorithm
- Optimal
- Page faults
- 9
- Hit ratio
- 55%
- Algorithm
- LRU
- Page faults
- 12
- Hit ratio
- 40%
MCA-105 Unit 4: File Systems, Devices and Secondary Storage
Pages 73 to 94, twelve sections. Access methods and five directory structures lead into contiguous, linked and indexed allocation and the inode maximum-size sum. Devices cover channels and block multiplexing; storage covers six disk-scheduling algorithms and RAID 0 to 6, then Linux permissions and file system calls. Count: 5 worked items, 1 C program with output, 9 diagrams, 13 short-answer and 10 long-answer questions.
| Algorithm | Cylinders moved |
|---|---|
| FCFS | 640 |
| SSTF | 236 |
| SCAN | 236 |
| LOOK | 208 |
Quick look: total head movement, queue 98, 183, 37, 122, 14, 124, 65, 67 with head at 53 (from page 88)
- Algorithm
- FCFS
- Cylinders moved
- 640
- Algorithm
- SSTF
- Cylinders moved
- 236
- Algorithm
- SCAN
- Cylinders moved
- 236
- Algorithm
- LOOK
- Cylinders moved
- 208
Race conditions and the critical-section problem in operating systems: excerpt from page 25 of the MCA-105 notes
Excerpt from page 25
Process synchronization: introduction
Cooperating processes and threads often share data. When they access that data at the same time, the result can be inconsistent. Process synchronization is the set of mechanisms that makes cooperating processes run in an orderly way, so the shared data stays consistent.
Race condition: the problem
Take a producer and a consumer that share an integer counter, initially 5. The producer runs counter++ and the consumer runs counter-- at the same time. In machine language, each statement becomes three steps: load counter into a register, change the register by one, and store the register back into counter.
Solved example: one bad interleaving
- T0: the producer loads
counter, so register1 = 5. - T1: the producer adds one, so register1 = 6.
- T2: the consumer loads
counter, so register2 = 5. - T3: the consumer subtracts one, so register2 = 4.
- T4: the producer stores register1, so
counter= 6. - T5: the consumer stores register2, so
counter= 4.
The correct value is 5. If T4 and T5 swap places, the answer becomes 6 instead. The final value depends on the order in which the two processes happened to run.
Key point
A race condition is a situation where several processes access and change the same data concurrently, and the outcome depends on the particular order of those accesses. To prevent it, only one process at a time may change the shared variable.
The critical-section problem
Consider n processes P0 to Pn-1. Each has a segment of code, its critical section, in which it may change common variables, update a table or write a file. The system must ensure that while one process runs in its critical section, no other process runs in its own. The critical-section problem is to design a protocol the processes can use to cooperate.
do {
[ entry section ] /* request permission */
critical section
[ exit section ] /* announce leaving */
remainder section
} while (true);How to write MCA-105 answers: Gantt-chart numericals, Banker's tables and Linux system-call programs
Unit questions reward structure over length. The exam tips inside the MCA-105 Operating Systems with Linux IPU notes point to the same habits across all four units.
- Scheduling numericals: write
TAT = CT − ATandWT = TAT − BTfirst, then the Gantt chart, the table and the averages. A neat chart and correct formulas still earn marks when one value slips. - Banker's algorithm: compute Need first, then show Work before and after each step.
- Page replacement and disk scheduling: fill frames column by column; for disk questions, state the head direction and whether the C-SCAN return sweep is counted.
- Linux questions: give the command, one option and a sample output. For system calls, add purpose and return value, then a short C program with its output.
Worked example: the convoy effect (page 37)
P1 = 24, P2 = 3 and P3 = 3 ms arrive together. Under FCFS in that order, waiting times are 0, 24 and 27, so the average is 51/3 = 17 ms. Order P2, P3, P1 drops it to 3 ms. Naming this the convoy effect completes the answer.
Avoid the page 31 slip: wait(mutex) before wait(empty) deadlocks a full bounded buffer. Practise this format on GGSIPU MCA important questions.
MCA-105 exam corner: 49 short-answer and 37 long-answer questions by unit
| Unit | Short answer | Long answer | Worked examples and numericals |
|---|---|---|---|
| Unit 1 | 12 | 8 | 2 |
| Unit 2 | 12 | 9 | 9 |
| Unit 3 | 12 | 10 | 10 |
| Unit 4 | 13 | 10 | 5 |
| Total | 49 | 37 | 26 |
MCA-105 exam questions and worked items per unit in the notes
- Unit
- Unit 1
- Short answer
- 12
- Long answer
- 8
- Worked examples and numericals
- 2
- Unit
- Unit 2
- Short answer
- 12
- Long answer
- 9
- Worked examples and numericals
- 9
- Unit
- Unit 3
- Short answer
- 12
- Long answer
- 10
- Worked examples and numericals
- 10
- Unit
- Unit 4
- Short answer
- 13
- Long answer
- 10
- Worked examples and numericals
- 5
- Unit
- Total
- Short answer
- 49
- Long answer
- 37
- Worked examples and numericals
- 26
The MCA-105 notes list 49 short-answer and 37 long-answer exam-style questions across 4 units, plus 26 worked examples and numericals and 4 C programs.
- Unit 1: Explain system calls, how one executes and their types with Linux examples. Pointer: trap and system-call table, three parameter-passing methods, then six categories with calls such as
fork()andchmod()(pages 9 to 10). - Unit 2: Explain the dining-philosophers problem with a semaphore solution and a deadlock-free monitor solution. Pointer: why the semaphore version deadlocks, then the
pickup()/putdown()monitor (pages 32 to 35). - Unit 3: Find the safe sequence with the Banker's algorithm. Pointer: with Available (3, 3, 2), the notes reach the safe sequence P1, P3, P4, P0, P2 (pages 54 to 56).
- Unit 4: What will
chmod 754 filedo? Pointer: owner rwx (7), group r-x (5), others r-- (4):rwxr-xr--(page 90).
More practice sits in the MCA-105 important questions.
MCA-105 and the MCA-163 Operating Systems with Linux lab, plus other GGSIPU MCA Sem 1 papers
Lab card: MCA-163 Operating Systems with Linux lab notes (0-2, 1 credit; no numbered practicals in the official PDF).
- Unit 1 Linux basics feed lab CO1 (installing Linux) and CO2 (Linux commands).
- Unit 2 scheduling and process calls feed lab CO3 (process management, IPC, CPU scheduling).
- Unit 3 Banker's algorithm and Unit 4 file system calls feed lab CO4 (system-call programs in C and a deadlock-avoidance simulation).
Other Semester 1 papers: MCA-101 Discrete Structures, MCA-103 Computer Networks, MCA-107 Database Management Systems, MCA-109 Object Oriented Programming and JAVA, the labs MCA-161, MCA-165 and MCA-167, MCA-169 Minor Project I and MCA-171 Professional Proficiency I (NUES).
Who writes and checks the MCA-105 OS with Linux notes?
- Prateek Talwar, author and editor of these notes. Founder, Unnati Educations; Associate Company Secretary (ACS), ICSI, membership no. 58704, since 15 May 2019; B.Com, University of Delhi (School of Open Learning), 2012. Author bio
- Ritik Rawat, subject reviewer. Senior Full Stack Developer at Unnati Educations with a B.Tech; he checks the computing content, C programs and Linux commands in these notes.
These GGSIPU MCA Sem 1 Operating Systems with Linux notes, 2026-27 edition, map every section to the MCA scheme applicable from session 2025-26. It was last updated on 14 October 2026 under our editorial policy. The same team prepares GGSIPU important questions for every course.
Do the MCA-105 notes cover the full GGSIPU syllabus?
Yes. Every topic listed for MCA-105 Units 1 to 4 in the 2025-26 MCA syllabus has its own section in the notes; no gap was found.
| Official unit | Official topics | Where in the notes | Status |
|---|---|---|---|
| Unit I | OS concept, components, operations, protection and security, computing environment; user and system view, services, system calls; single and multiprocessor systems; five OS types; processes, IPC, threads; Linux introduction and basic commands | Sections 1 to 6, pages 5 to 21 | Covered |
| Unit II | Critical-section problem, Bakery algorithm, synchronization hardware, semaphores, classical problems, critical regions, monitors; scheduling criteria and algorithms, multilevel and multilevel feedback queues; Linux process commands and system calls | Sections 1 to 10, pages 25 to 47 | Covered |
| Unit III | Deadlock characterization, resource allocation graph, prevention, avoidance, detection, recovery, Banker's algorithm; contiguous allocation, fragmentation, paging, segmentation; demand paging, page replacement, frame allocation, thrashing; Linux memory commands and system calls | Sections 1 to 12, pages 51 to 70 | Covered |
| Unit IV | File-system interface, access methods, directory structure, file-system implementation, allocation, free-space management; device types, channels, multiple paths, block multiplexing; disk structure, scheduling, management, RAID; Linux file commands and system calls | Sections 1 to 12, pages 74 to 92 | Covered |
MCA-105 official syllabus topics mapped to the notes
- Official unit
- Unit I
- Official topics
- OS concept, components, operations, protection and security, computing environment; user and system view, services, system calls; single and multiprocessor systems; five OS types; processes, IPC, threads; Linux introduction and basic commands
- Where in the notes
- Sections 1 to 6, pages 5 to 21
- Status
- Covered
- Official unit
- Unit II
- Official topics
- Critical-section problem, Bakery algorithm, synchronization hardware, semaphores, classical problems, critical regions, monitors; scheduling criteria and algorithms, multilevel and multilevel feedback queues; Linux process commands and system calls
- Where in the notes
- Sections 1 to 10, pages 25 to 47
- Status
- Covered
- Official unit
- Unit III
- Official topics
- Deadlock characterization, resource allocation graph, prevention, avoidance, detection, recovery, Banker's algorithm; contiguous allocation, fragmentation, paging, segmentation; demand paging, page replacement, frame allocation, thrashing; Linux memory commands and system calls
- Where in the notes
- Sections 1 to 12, pages 51 to 70
- Status
- Covered
- Official unit
- Unit IV
- Official topics
- File-system interface, access methods, directory structure, file-system implementation, allocation, free-space management; device types, channels, multiple paths, block multiplexing; disk structure, scheduling, management, RAID; Linux file commands and system calls
- Where in the notes
- Sections 1 to 12, pages 74 to 92
- Status
- Covered
Official source: GGSIPU MCA Scheme of Examination and Detailed Syllabus, from A.S. 2025-26 onwards (approved by BoS of USIC&T, 28 July 2025).
Every course in GGSIPU notes is mapped to its official PDF the same way.
MCA-105 OS with Linux notes FAQs
How do I get the full MCA-105 notes?
Message Unnati Educations on WhatsApp at 9899436384 using the Get Full Notes button on this page. The full MCA-105 notes are sold only as a printed book; there is no PDF edition. Delivery takes 5 to 7 days at most, depending on your location. Before ordering, open View Sample PDF in the header to see the cover, contents and one page from each of the four units.
Do the MCA-105 notes follow the 2025-26 GGSIPU MCA syllabus?
Yes. The notes were checked against the MCA scheme approved by the USIC&T Board of Studies on 28 July 2025, which applies from session 2025-26 at affiliated institutes. Each official topic in Units I to IV, including the Bakery algorithm and block multiplexing, maps to a numbered section and page in the syllabus map above.
What is the passing mark for MCA-105?
The MCA-105 end-term question paper carries 60 marks: a 12-mark compulsory Q1 plus four 12-mark unit questions. The MCA scheme of examination states pass marks as 40%, which is 40 out of 100 for every paper. End-term minimums, re-appear rules and result rules come from GGSIPU Ordinance 11, which the scheme says governs the programme.
Which MCA-105 unit has the most numericals?
Unit 3 has the most, with 10 worked items, including the Banker's safety check, first, best and worst fit, paging and segmentation address translation, two effective-access-time sums and page replacement. Unit 2 follows with 9, including one five-process question solved six ways. Unit 4 adds the six disk-scheduling algorithms on one request queue, and Unit 1 has the fewest.
Are Linux commands and system calls covered in the MCA-105 notes?
Yes. Each unit ends with its own Linux section: basic commands on pages 19 to 21, process commands and system calls on pages 45 to 47, memory commands and calls on pages 69 to 70, and file commands and calls on pages 90 to 92. Four C programs show fork(), wait(), mmap() and a file copy with read() and write().
Do the MCA-105 notes include the MCA-163 lab?
No. This book covers the MCA-105 theory paper only. MCA-163 is a separate 1-credit lab with two practical hours a week, and the official PDF lists its four course outcomes without numbered practicals. The theory notes still help there, because their C programs and terminal sessions use the same system calls the lab outcomes name.
Get the full MCA-105 Operating Systems with Linux Notes on WhatsApp
What the printed MCA-105 notes book contains, unit by unit
- Part
- Cover and contents
- Pages
- 1 to 3
- Sections
- -
- Exam questions
- -
- Part
- Unit 1
- Pages
- 4 to 23 (20)
- Sections
- 6
- Exam questions
- 20
- Part
- Unit 2
- Pages
- 24 to 49 (26)
- Sections
- 10
- Exam questions
- 21
- Part
- Unit 3
- Pages
- 50 to 72 (23)
- Sections
- 12
- Exam questions
- 22
- Part
- Unit 4
- Pages
- 73 to 94 (22)
- Sections
- 12
- Exam questions
- 23
These Operating Systems with Linux notes in English come only as a 94-page printed book, not a PDF. Inside: 26 worked examples and numericals, 4 C programs, 31 diagrams, a revision table per unit and 86 exam-style questions. The price is shared on WhatsApp. Delivery: within 5 to 7 days at most; the exact time may vary with your location.
Order the MCA-105 notes book on WhatsApp (4 units, 94 pages)
Unnati Educations is an independent education provider based in Vikaspuri, Delhi. We are not affiliated with, authorised by, or endorsed by Guru Gobind Singh Indraprastha University (GGSIPU). 'GGSIPU' and 'IPU' are used only to describe the syllabus our notes follow. For official information, visit ipu.ac.in.
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