Variable (or Dynamic) Partitioning in Operating System
In computer science, the process of dividing computer memory into multiple sections to allow multiple programs to run at the same time is known as memory partitioning. Memory partitioning can be classified into two types, namely, fixed partitioning and variable (or dynamic) partitioning. In this blog, we will focus on the latter, dynamic partitioning.
Dynamic partitioning is a technique of allocating memory to processes during runtime in an operating system. It allows the operating system to create and delete memory partitions dynamically, as and when needed by the processes. Unlike fixed partitioning, dynamic partitioning provides more flexibility and better memory utilization as the size of the partition can be adjusted as per the needs of the process.
Dynamic partitioning algorithms can be further divided into two categories: first-fit, best-fit, and worst-fit. The first-fit algorithm allocates the first available memory block that fits the size requirement of the process. The best-fit algorithm allocates the smallest block of memory that fits the size requirement of the process. The worst-fit algorithm allocates the largest available block of memory. The aim of these algorithms is to minimize memory waste and fragmentation.
Memory fragmentation is a common issue in dynamic partitioning. It occurs when small blocks of memory are left unallocated after a process terminates. These small blocks are known as holes and cannot be used by any process. The operating system must periodically consolidate these holes to minimize memory waste.
The benefits of dynamic partitioning are many. Firstly, it provides better memory utilization compared to fixed partitioning as the size of the partition can be adjusted as per the needs of the process. Secondly, it allows the operating system to allocate memory efficiently and dynamically to meet the requirements of the processes. Thirdly, it provides a higher degree of flexibility compared to fixed partitioning as processes can be allocated and deallocated memory as and when needed.
Dynamic partitioning algorithms are implemented in various operating systems such as Windows, Linux, and Unix. In Windows, dynamic partitioning is implemented using the Virtual Memory Manager (VMM) that provides a virtual memory space to the processes. In Linux, dynamic partitioning is implemented using the Memory Management Unit (MMU) that provides virtual memory to the processes.
In conclusion, dynamic partitioning is a powerful technique in operating systems that allows for better memory utilization, efficient memory allocation, and higher flexibility. It is implemented in various operating systems and is an important aspect of memory management in modern computers. Understanding dynamic partitioning is essential for anyone looking to understand the inner workings of an operating system and how it manages memory.
