Patent ID: 9519548
Filing Date: 2016-12-13
CPC Classification: G06F

Claim Text:
1. A method of backing up a virtual machine running in a first computer system, the first computer system having a memory management unit that manages mappings of virtual addresses to physical memory pages using hierarchically-arranged page tables, the method comprising: scanning entries of a first page table and a second page table distinct from the first page table, an entry in the first page table and an entry in the second page table each referencing a common physical memory page; determining that a first section of the common physical memory page is dirty based on the entry of the first page table that references the common physical memory page and determining that a second section of the common physical memory page is not dirty based on the entry of the second page table that references the common physical memory page; and transmitting at least a portion of the first section of the common physical memory page to a second computer system.