DCW Prefix Parameter Data Embedding Truncated Locate Record Commands
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Solution Overview
Problem
Current I/O architectures, particularly those using fibre channel protocols for device command word (DCW) processing, are limited in packaging multiple locate record commands due to restricted transport layer size, hindering efficient execution of complex instruction chains.
Innovation Solution
A method where a first locate record command is packaged into DCW prefix parameter data, with subsequent truncated locate record commands embedded as concatenations, sharing seek and search argument offsets to minimize byte usage, allowing for efficient packaging of multiple commands within the limited DCW protocol space.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple locate record commands are packaged into a single DCW prefix parameter data structure, then the number of commands that can be executed in one I/O operation increases, but the transport layer size limitation of DCW protocols restricts the maximum number of commands that can be packaged
Solution Approach 1:
The patent embeds multiple truncated locate record commands within a single DCW prefix parameter data structure. Each truncated command is nested as a domain within the prefix parameters, allowing multiple commands to be contained in one transport unit. This nesting approach maximizes the use of available transport layer space while exceeding the traditional limit of one locate record command per DCW.
Solution Approach 2:
The locate record command is segmented into truncated versions that fit within the DCW prefix parameter structure. Each truncated command contains only the essential unique parameters (search argument, intent count, transfer length factor) while sharing common parameters with the first locate record command. This segmentation allows multiple commands to be packaged within the size constraints of the DCW protocol.
2Quantity of substance
If truncated locate record commands are embedded in DCW prefix parameter data, then byte usage is minimized through shared parameters, but the complexity of calculating seek arguments with offsets increases
Solution Approach 1:
The first locate record command in the chain establishes the base seek argument. Subsequent truncated commands calculate their seek arguments by applying offsets to this base value. This preliminary establishment of the base seek argument simplifies the overall calculation process, as each subsequent command only needs to compute a simple offset addition rather than determining the complete seek argument from scratch.
Solution Approach 2:
The patent changes the representation of seek arguments in truncated commands by using offset values relative to the first command's seek argument. This parameter transformation reduces the byte usage for each truncated command while maintaining the ability to correctly identify the target tracks. The offset-based approach balances compactness with computational simplicity.
Data Source
AI summary
A method of packaging locate record commands for device command word (DCW) processing is provided. A first locate record command is packaged into DCW prefix parameter data. The first locate record command includes first search and first seek arguments, a first intent count argument, a first transfer length factor argument, and a plurality of remaining arguments. A plurality of truncated locate record commands is embedded in the DCW prefix parameter data as concatenations to the first locate record command. Each of the plurality of truncated locate record commands include a unique search argument, intent count argument, and transfer length factor argument. Seek argument parameters for each of the plurality of truncated locate record commands are calculated by taking an offset from the first seek argument and the first search argument, applying the offset to each of the plurality of truncated locate record commands. The plurality of remaining arguments is shared.