UNIX operating system allows user to fully utilize the physical memory installed in the system as well as part of the hard disk called swap space which have been designated for use by the kernel while the physical memory is insufficient to handle the tasks. When the original contents are needed again, they are read back into memory. In computing, virtual memory is a ... UNIX Specification also uses the term "locked" in the specification for mlock (), as do the mlock man pages on many Unix-like systems. This is the memory which can be used for both showing and storing data. Virtual memory is simulated memory that is written to a file on the hard drive. When we talk about memory in this article, we usually mean random access memory . Linux memory information Random access memory. It acts as an interface between the actual memory and applications running on the machine. Virtual Memory is the memory that applications/programs running on a machine see and to which they interact. Virtual memory is needed whenever your computer doesn't have space in the physical memory A demand paging mechanism is very much similar to a paging system with swapping where processes stored in the secondary memory and pages are loaded only on demand, not in advance. Virtual memory has a very important role in the operating system. The main visible advantage of this scheme is that programs can be larger than physical memory. Linux supports virtual memory, that is, using a disk as an extension of RAM so that the effective size of usable memory grows correspondingly. Virtual memory uses hardware and software to allow a computer to compensate for physical memory shortages, by temporarily transferring data from random access memory to disk storage. Virtual memory is a very common technique used in the operating systems (OS) of computers. It allows us to run more applications on the system than we have enough physical memory to support. Segments of memory are stored on the hard drive known as pages. The picture shows the Virtual Memory settings window in Microsoft Windows. That file is often called page file or swap file. Virtual-real operation. From this window, you can … When a segment of memory is requested that is stored in virtual memory, it is loaded into the actual memory address. Virtual memory is a component of most operating systems, such as MAC OS, Windows and Linux. Typically we will find in this type of memory the programs that are running on the system, including the Linux kernel itself. Virtual memory is a method of using the computer hard drive to provide extra memory for the computer. A computer can address more memory than the amount physically installed on the system. Whether the application is accessing a memory location that is resident in the RAM or a location in SWAP will be transparent to the application and that is handled by this interface. The kernel will write the contents of a currently unused block of memory to the hard disk so that the memory can be used for another purpose. In OS/VS1 and similar OSes, some parts of systems memory are managed in "virtual-real" mode, called "V=R". In this mode every virtual address corresponds to the same real address. Virtual Memory is a storage mechanism which offers user an illusion of having a very big main memory. Virtual Memory. This extra memory is actually called virtual memory and it is a section of a hard disk that's set up to emulate the computer's RAM..