Selective pruning of a system configuration model for system reconfigurations

A computer program product for reconfiguration of a computing environment from an as-is input/output (I/O) configuration to a to-be I/O configuration, the computer program product comprising:

• one or more computer-readable tangible storage devices and program instructions stored on at least one of the one or more computer-readable tangible storage devices, wherein the program instructions are executable by a computer, the program instructions comprising:
• program instructions to normalize a first hierarchical model of the as-is I/O configuration and a second hierarchical model of the to-be I/O configuration, wherein the first and the second hierarchical models each comprise a hierarchical structure of leaf and non-leaf nodes, and wherein normalizing comprises the application of syntactical transformation rules to the first and the second hierarchical models such that their respective I/O configurations are defined in a syntactically consistent manner across the first and the second hierarchical models;
• program instructions to create a first hash tree representation of the first hierarchical model and a second hash tree representation of the second hierarchical model, wherein nodes of the first hash tree representation are checksum values calculated for leaf and non-leaf nodes of the first hierarchical model, and wherein nodes of the second hash tree representation are checksum values calculated for leaf and non-leaf nodes of the second hierarchical model, and wherein nodes of the first and second hash tree representations reflect the hierarchical structure of the first and the second hierarchical models, respectively;
• and
• program instructions to prune one or more nodes of the first hash tree representation and the second hash tree representation where checksum values are equal up to a root node of the first hash tree representation and a root node of the second hash tree representation.

A computer system for reconfiguration of a computing environment from an as-is input/output (I/O) configuration to a to-be I/O configuration, the computer system comprising:

• one or more processors, one or more computer-readable memories, one or more computer-readable tangible storage devices, and program instructions stored on at least one of the one or more computer-readable tangible storage devices 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 normalize a first hierarchical model of the as-is I/O configuration and a second hierarchical model of the to-be I/O configuration, wherein the first and the second hierarchical models each comprise a hierarchical structure of leaf and non-leaf nodes, and wherein normalizing comprises the application of syntactical transformation rules to the first and the second hierarchical models such that their respective I/O configurations are defined in a syntactically consistent manner across the first and the second hierarchical models;
• program instructions to create a first hash tree representation of the first hierarchical model and a second hash tree representation of the second hierarchical model, wherein nodes of the first hash tree representation are checksum values calculated for leaf and non-leaf nodes of the first hierarchical model, and wherein nodes of the second hash tree representation are checksum values calculated for leaf and non-leaf nodes of the second hierarchical model, and wherein nodes of the first and second hash tree representations reflect the hierarchical structure of the first and the second hierarchical models, respectively;
• and
• program instructions to prune one or more nodes of the first hash tree representation and the second hash tree representation where checksum values are equal up to a root node of the first hash tree representation and a root node of the second hash tree representation.