Up to now, the mainstream code of Xen does not have a complete solution for memory deduplication. The Xen-dedup is based on the core algorithms used in UKSM with further improvement. It can efficiently scan the Xen guests'(domU) virtual memory and merge the duplicated pages at ultra high speed.
Same features as UKSM (refer to UKSM project for more details):
- Full system scan.
- Super quiet CPU usage.
- Ultra scan speed and CPU efficiency.
- Thrashing area avoidance.
New features in Xen-dedup:
- Zero config: Unlike other Xen memory features like page-sharing, XCP, etc, Xen-dedup does not need user land (in dom0) helper or configuration to work.
- xl tool integration: The full control (e.g. tuning internal parameter in very rare cases ) of Xen-dedup is integrated in to the Xen tool of xl
- Balloon drivers alternative: For guest OS without balloon driver, the returning free memory in guest can be done by a user program allocating a lot of pages and filling them with 0.
If you are running business based on Xen virtual machines, then Xen-dedup is a must have technology.