Major page fault: If the page is not loaded in memory at the time the fault is stated, then it is named major or hard page fault. The handler in the machine requires to search a free page in memory, or select a page in memory to be used for this page's data, write out the data in that page if it hasn't already been carried out since it was last changed, check that page as not being loaded into memory, read the data for this page into the page, and then create the entry for that page in the memory management unit point to the page in memory and show that the page is loaded in memory drive. Major faults are more costly than minor page faults and include disk latency to the halted program's execution. This is the function used by an operating system to raise the amount of program memory available on demand.