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UML Clustering
Spread one UML instance across multiple hosts
- DSM initially - fault pages between hosts
- Later do it for real, maybe using Compaq SSI work
UML will have access to combined resources of hosts
- analogous to physical cluster having access to combined hardware of members
Notes:
It's possible to spread a UML instance over multiple hosts in the same way that it's possible to spread a single native kernel image across multiple physical machines in an SSI cluster.
A fairly easy, but easy way to do this is to implement a mechanism for faulting pages from one host to another. So, when a thread on one host accesses a page that's on another host, it would fault, and the fault handler would copy the page across.
This would be highly inefficient. A better way would be to implement an RPC mechanism such as the Compaq SSI work, rather than this DSM.
Having done this, you would have a virtual cluster running over multiple hosts which would be fairly similar to a physical cluster running across multiple physical machines.
This virtual cluster would have access to the combined resources of the hosts in the same way that a physical cluster has access to the combined resources of its members.