Operating System Interview Questions and Answers

Question - 31 : - What is a deadlock?

Answer - 31 : - What is a deadlock?- It is a condition where a group of two or more waiting for the resources currently in use by other processes of the same group. - In this situation every process is waiting for an event to be triggered by another process of the group. - Since no thread can free up the resource a deadlock occurs and the application hangs.

Question - 32 : - What conditions for deadlock to occur?are the necessary

Answer - 32 : - 1. At least one resource should be occupied in a non-sharable condition. 2. A process holding at least one resource is waiting for more resources currently in use by other processes. 3. It is not possible to pre-empt the resource. 4. There exists a circular wait for processes.

Question - 33 : - what are Name the functions constituting the OS's memory management.

Answer - 33 : - 1. Memory allocation and de-allocation 2. Integrity maintenance 3. Swapping 4. Virtual memory

Question - 34 : - what are name the different types of memory?

Answer - 34 : - a. Main memory also called primary memory or RAM b. Secondary memory or backing storage c. Cache d. Internal process memory

Question - 35 : - What is compaction.

Answer - 35 : - What is compaction.During the process of loading and removal of process into and out of the memory, the free memory gets broken into smaller pieces. These pieces lie scattered in the memory. Compaction means movement of these pieces close to each other to form a larger chunk of memory which works as a resource to run larger processes.

Question - 36 : - What are page frames?

Answer - 36 : - Page frames are the fixed size contiguous areas into which the main memory is divided by the virtual memory.

Question - 37 : - Differentiate between logical and physical address.

Answer - 37 : - Physical addresses are actual addresses used for fetching and storing data in main memory when the process is under execution. Logical addresses are generated by user programs. During process loading, they are converted by the loader into physical address.

Question - 38 : - When does page fault error occur?

Answer - 38 : - It occurs when a page that has not been brought into main memory is accessed.

Question - 39 : - Explain thrashing.

Answer - 39 : - - In virtual memory system, thrashing is a high page fault scenario. It occurs due to under-allocation of pages required by a process. - The system becomes extremely slow due to thrashing leading to poor performance.

Question - 40 : - What are the basic functions of file management in OS?

Answer - 40 : - 1. Creation and deletion of files/ directories. 2. Support of primitives for files/ directories manipulation. 3. Backing up of files on storage media. 4. Mapping of files onto secondary storage.