O(1) virtual machine (vm) snapshot management

A computer program product for managing a virtual machine snapshot in O(1) time, the computer program product comprising one or more computer readable storage medium and program instructions stored on at least one of the one or more computer readable storage medium, the program instructions comprising:

• program instructions to initially store data, by a computer host operating system, from a virtual machine executing under the host operating system, to a first host operating system managed data block;
• program instructions to create, by the computer host operating system, a first pointer that points to the first host operating system managed data block and associates the virtual machine to the data stored in the first host operating system managed data block;
• program instructions to initialize, by the computer host operating system, a first value associated with the first host operating system managed data block indicating the number of pointers created to associate the virtual machine to the first host operating system managed data block;
• program instructions to receive, by the computer host operating system, a request to create a snapshot of the virtual machine;
• program instructions to create, by the computer host operating system, a second pointer replicating the first pointer;
• and
• program instructions to increment, by the computer host operating system, the first value associated with the first host operating system managed data block.

A computer system for managing a virtual machine snapshot in O(1) time, the computer system comprising one or more processors, one or more computer readable memories, one or more computer readable tangible storage medium, and program instructions stored on at least one of the one or more storage medium for execution by at least one of the one or more processors via at least one of the one or more memories, the program instructions comprising:

• program instructions to initially store data, by a computer host operating system, from a virtual machine executing under the host operating system, to a first host operating system managed data block;
• program instructions to create, by the computer host operating system, a first pointer that points to the first host operating system managed data block and associates the virtual machine to the data stored in the first host operating system managed data block;
• program instructions to initialize, by the computer host operating system, a first value associated with the first host operating system managed data block indicating the number of pointers created to associate the virtual machine to the first host operating system managed data block;
• program instructions to receive, by the computer host operating system, a request to create a snapshot of the virtual machine;
• program instructions to create, by the computer host operating system, a second pointer replicating the first pointer;
• and
• program instructions to increment, by the computer host operating system, the first value associated with the first host operating system managed data block.