Book excerpt: Our 1500+ Operating Systems questions and answers focuses on all areas of Operating Systems subject covering 100+ topics in Operating Systems. These topics are chosen from a collection of most authoritative and best reference books on Operating Systems. One should spend 1 hour daily for 15 days to learn and assimilate Operating Systems comprehensively. This way of systematic learning will prepare anyone easily towards Operating Systems interviews, online tests, examinations and certifications. You can watch basic Operating Systems video lectures by visiting our YouTube channel IT EXAM GURUJI. Highlights ------------  1500+ Basic and Hard Core High level Multiple Choice Questions & Answers in Operating Systems with explanations.  Prepare anyone easily towards Operating Systems interviews, online tests, Government Examinations and certifications.  Every MCQ set focuses on a specific topic in Operating Systems. Who should Practice these Operating Systems Questions?  Anyone wishing to sharpen their skills on Operating Systems.  Anyone preparing for aptitude test in Operating Systems.  Anyone preparing for interviews (campus/off-campus interviews, walk-in interview & company interviews)  Anyone preparing for entrance examinations and other competitive examinations.  All – Experienced, Freshers and Students. Inside- ------- Operating System Basics -----------------------------------------------------------------------6 Processes ----------------------------------------------------------------------------------------- 8 Process Control Block--------------------------------------------------------------------------10 Process Scheduling Queues----------------------------------------------------------------- 12 Process Synchronization----------------------------------------------------------------------15 Process Creation------------------------------------------------------------------------------- 17 Inter Process Communication---------------------------------------------------------------19 Remote Procedure Calls-----------------------------------------------------------------------21 Process Structures------------------------------------------------------------------------------23 CPU Scheduling----------------------------------------------------------------------------------26 CPU Scheduling Benefits----------------------------------------------------------------------28 CPU Scheduling Algorithms I --------------------------------------------------------------- 31 CPU Scheduling Algorithms II ---------------------------------------------------------------34 Critical Section (CS) Problem and Solutions- --------------------------------------------37 Semaphores I -----------------------------------------------------------------------------------39 Semaphores II ----------------------------------------------------------------------------------43 The Classic Synchronization Problems----------------------------------------------------46 Monitors------------------------------------------------------------------------------------------49 Atomic Transactions---------------------------------------------------------------------------51 Deadlock -----------------------------------------------------------------------------------------54 Deadlock Prevention---------------------------------------------------------------------------56 Deadlock Avoidance ---------------------------------------------------------------------------59 Deadlock Detection ----------------------------------------------------------------------------63 Deadlock Recovery-----------------------------------------------------------------------------65 Memory Management –Swapping Processes I -----------------------------------------67 Memory Management – Swapping Processes II -------------------------------------- 70 Memory Management ---------------------------------------------------------------------- 73 Memory Allocation I ------------------------------------------------------------------------- 75 Memory Allocation II --------------------------------------------------------------------------78 Paging – I -----------------------------------------------------------------------------------------80 Paging – II ----------------------------------------------------------------------------------------83 Segmentation------------------------------------------------------------------------------------86 I/O System – Application I/O Interface – I -----------------------------------------------89 I/O System – Application I/O Interface – II ----------------------------------------------92 I/O System – Kernel I/O Subsystems ------------------------------------------------------95 RTOS ----------------------------------------------------------------------------------------------97 Implementing RT Operating Systems -----------------------------------------------------99 Implementing RT Operating Systems ----------------------------------------------------101 Real Time CPU Scheduling – I --------------------------------------------------------------103 Real Time CPU Scheduling – II -------------------------------------------------------------106 Multimedia Systems -------------------------------------------------------------------------108 Multimedia System – Compression – I --------------------------------------------------110 Multimedia System – Compression – II--------------------------------------------------113 Multimedia System – Compression – III-------------------------------------------------115 CPU and Disk Scheduling -------------------------------------------------------------------117 Network Management ----------------------------------------------------------------------119 Security – User Authentication -----------------------------------------------------------122 Security – Program and System Threats-------------------------------------------------125 Security – Securing Systems and Facilities ---------------------------------------------129 Security – Intrusion Detection ------------------------------------------------------------132 Security – Cryptography --------------------------------------------------------------------135 Secondary Storage ---------------------------------------------------------------------------137 Linux ---------------------------------------------------------------------------------------------139 Threads -----------------------------------------------------------------------------------------141 User and Kernel Threads -------------------------------------------------------------------143 Multi Threading Models --------------------------------------------------------------------146 The Fork and exec System Calls -----------------------------------------------------------148 Thread Cancellation -------------------------------------------------------------------------150 Signal Handling -------------------------------------------------------------------------------152 Thread Pools ----------------------------------------------------------------------------------155 Virtual Memory -------------------------------------------------------------------------------157 Virtual Memory – Demand Paging -------------------------------------------------------159 Page Replacement Algorithms – I- -------------------------------------------------------162 Page Replacement Algorithms – II--------------------------------------------------------165 Allocation of Frames -------------------------------------------------------------------------168 Virtual Memory – Thrashing ---------------------------------------------------------------171 File System Concepts ------------------------------------------------------------------------174 File System Implementation----------------------------------------------------------------176 File System Interface Access Methods – I-----------------------------------------------178 File System Interface Access Methods – II----------------------------------------------180 File System Interface Directory Structure – I-------------------------------------------182 File System Interface Directory Structure – II------------------------------------------185 File System Interface Mounting and Sharing ------------------------------------------188 File System Interface Protection ----------------------------------------------------------191 File System ImplementationAllocation Methods – I----------------------------------194 File System Implementation–Allocation Methods – II-------------------------------197 File System Implementation–Allocation Methods – III------------------------------200 File System Implementation – Performance - -----------------------------------------203 File System Implementation – Recovery -----------------------------------------------205 File System Implementation – Network File System –I------------------------------207 File System Implementation – Network File System –II---------------------------- 209 I/O Subsystem ---------------------------------------------------------------------------------211 Disk Scheduling – I----------------------------------------------------------------------------213 Disk Scheduling – II---------------------------------------------------------------------------215 Disk Management ----------------------------------------------------------------------------218 Swap Space Management ------------------------------------------------------------------220 RAID Structure – I-----------------------------------------------------------------------------223 RAID Structure – II----------------------------------------------------------------------------226 Tertiary Storage -------------------------------------------------------------------------------229 Protection – Access Matrix -----------------------------------------------------------------231 Protection Concepts -------------------------------------------------------------------------235 Security -----------------------------------------------------------------------------------------237 Memory Protection --------------------------------------------------------------------------239 Protection – Revocation of Access Rights ----------------------------------------------242 Distributed Operating System -------------------------------------------------------------245 Types & Resource Sharing - ----------------------------------------------------------------247 D-OS Network Structure & Topology - --------------------------------------------------250 Robustness of Distributed Systems ------------------------------------------------------252 Distributed File System – I------------------------------------------------------------------254 Distributed File System – II-----------------------------------------------------------------256 Distributed File System – III----------------------------------------------------------------258 Distributed Coordination -------------------------------------------------------------------260 Distributed Synchronization ---------------------------------------------------------------263