Transparent page sharing (TPS) is a memory management technology in virtualization that condenses redundant memory pages on a host into one page.
Identical memory pages can exist when multiple VMs run the same operating system. The hypervisor discovers redundancies by assigning hash values to pages and comparing them bit-by-bit when hash values match.
If the hypervisor identifies identical memory pages on multiple virtual machines (VMs) on a host, it shares them among virtual machines (VMs) with pointers. This frees up memory for new pages. If a VM's information on that shared page changes, the hypervisor writes the memory to a new page and readdresses a pointer.
Transparent page sharing is not available for large memory pages. Typically, only small memory pages are identical.