This article is part of an Essential Guide, our editor-selected collection of our best articles, videos and other content on this topic. Explore more in this guide:
9. - Terms to know for virtualization automation: Read more in this section
Explore other sections in this guide:
- 1. - Benefitting from task automation and workflow orchestration
- 2. - Automation is a must-learn technology for IT pros
- 3. - Finding a data center automation balance
- 4. - Expert advice: Use common sense when devising an automation strategy
- 5. - How to avoid manual resource allocation
- 6. - IT process automation in a Hyper-V environment
- 7. - What you should know to get the most out of vCenter Orchestrator
- 8. - Workflow automation software showdown: Citrix, Microsoft and VMware
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.