Using virtual disk in virtual machine live migration

摘要

Systems and methods for implementing lazy disk I/O in virtual machine live migration. An example method may comprise: determining, by a first computer system, that contents of a memory page mapped into an address space of a virtual machine undergoing live migration from a second computer system to the first computer system is stored on a network-accessible virtual disk; storing, in a memory data structure, a mapping of an address of the memory page to an identifier of a location of the memory page on the virtual disk; and responsive to detecting an access to the memory page by the virtual machine, storing in a memory mapped into the address space of the virtual machine the memory page retrieved from the location of the memory page on the virtual disk.

主权项

1. A method, comprising:
determining, by a processor of a first computer system, that contents of a memory page mapped into an address space of a virtual machine undergoing live migration from a second computer system to the first computer system is stored on a network-accessible virtual disk; storing, in a memory data structure, a mapping of an address of the memory page to an identifier of a location of the memory page on the virtual disk; setting a source bit in a page table entry associated with the memory page, the source bit indicating that the contents of the memory page has been stored on the virtual disk; detecting an access to the memory page by the virtual machine; responsive to ascertaining that the source bit is set, retrieving the contents of the memory page from the location on the virtual disk associated with the memory page by the mapping stored in the data structure; and storing the contents of the memory page in a memory range mapped into the address space of the virtual machine.