Logging pages accessed from I/O devices

A method of tracking page state changes, the method comprising:

• receiving, at an input/output (I/O) device communicatively coupled to a host having a physical memory, a command from the host to monitor page state changes in a first page of the physical memory allocated to a process executing on the host;
• modifying, by the I/O device, data stored in a first portion of the first page based on a request;
• recording, by the I/O device, the modification to a bitmap by setting a bit in the bitmap that corresponds to a location of the data in the physical memory;
• storing, by the I/O device, the bit in a first buffer in a general purpose memory of the host;
• and
• copying, by the I/O device or the host, the first portion of the first page indicated by the bitmap in the first buffer to a second portion of a second page of physical memory, wherein the second page of physical memory can be in the physical memory of the host, or in a second physical memory of a second host,
• wherein the bit denotes a predetermined portion of the first page such that copying the first portion of the first page indicated by the bitmap in the first buffer to a second portion of a second page of physical memory comprises copying only the predetermined portion of the first page and not copying the whole first page.