Memory virtualization


1. A technique that gives an application program the impression that it has its own contiguous logical memory independent of available physical memory.

2. Memory virtualization is a generalization of the concept of virtual memory.

3. Virtual memory makes application programming easier to hiding fragmentation of physical memory.

4. In virtual memory implementation, a memory address space is divided into contiguous blocks of fixed size pages.

5. Paging saves inactive memory pages onto the disk and brings them back to physical memory when required.

6. The space used by VMM(Virtual Memory Monitor) on the disk is known as a “Swap File”.

7. Swap is a portion of the local storage environment that is designated as memory to the host system.

8. The hosts see the local swap as additional addressable memory locations and does not delineate between RAM and Swap.

9. High bandwidth, low latency environments are making use of memory virtualization as well.

Benefits to use memory virtualization:

1. Higher memory utilization by sharing contents and consolidating more virtual machines on a physical host.

2. Ensuring some memory space exists before halting services until memory frees up.

3. Access to more memory than the chassis can physically allow.

4. Advanced server virtualization functions, like live migrations.