Abstract: In part, the invention relates to a system and method for writing checkpointing data to a computer having a standby virtual machine for each checkpointed component on a computer having an active virtual machine. In one embodiment, the checkpointing data is processed on a per virtual machine basis. This is performed in a way that allows checkpointing data packets from multiple sources to be transferred asynchronously, subsequently reassembled into a coherent checkpoint message, and applied asynchronously.

Abstract: A method of migrating memory from a primary computer to a secondary computer. In one embodiment, the method includes the steps of: (a) waiting for a checkpoint on the primary computer; (b) pausing the primary computer; (c) selecting a group of pages of memory to be transferred to the secondary computer; (d) transferring the selected group of pages of memory and checkpointed data; (e) restarting the primary computer; (f) waiting for a checkpoint on the primary computer; (g) pausing the primary computer; (h) selecting another group of pages of memory to be transferred; (i) transferring the other selected group of pages of memory and data checkpointed since the previous checkpoint to the secondary computer; (j) restarting the primary computer; and (k) repeating steps (f) through (j) until all the memory of the primary computer is transferred.

Abstract: In part, the invention relates to a system and method for writing checkpointing data to a computer having a standby virtual machine for each checkpointed component on a computer having an active virtual machine. In one embodiment, the checkpointing data is processed on a per virtual machine basis. This is performed in a way that allows checkpointing data packets from multiple sources to be transferred asynchronously, subsequently reassembled into a coherent checkpoint message, and applied asynchronously.