Storage Copy Command Mapping for Atomic Writes Without Buffers
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Solution Overview
Problem
Existing data storage management systems face challenges in maintaining copy command atomicity without requiring additional buffer space or delaying non-copy commands, particularly when handling overlapping commands in data storage devices.
Innovation Solution
Implementing a method that includes the initial insertion of a blocking NOP command across the LBAs of copy-write subcommands and mapping these subcommands to a shadow storage address space to maintain atomicity, allowing for autonomous execution without additional buffer space or delaying non-copy commands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If copy-write subcommands are executed with atomicity guarantee, then data consistency is improved, but execution efficiency deteriorates due to blocking non-copy commands
Solution Approach 1:
The patent segments the storage address space into a normal address space and a shadow address space. Copy-write subcommands are mapped to the shadow address space, while non-copy commands operate in the normal address space. This segmentation allows parallel execution of copy and non-copy commands without mutual blocking, maintaining atomicity in the shadow space while improving overall execution efficiency.
2Reliability
If additional buffer space is allocated to maintain copy command atomicity, then atomicity is improved, but resource allocation deteriorates
Solution Approach 1:
The patent introduces a shadow address space as an additional dimensional layer for storing copy-write data. Instead of using additional buffer space within the same address space, the solution creates a parallel address space dimension where copy operations can proceed without interfering with non-copy operations in the normal address space, thereby maintaining atomicity without consuming extra buffer resources.
3Reliability
If non-copy commands are delayed to maintain copy command atomicity, then atomicity is improved, but response time deteriorates
Solution Approach 1:
The patent creates a shadow copy of the address space specifically for handling copy-write operations. Non-copy commands continue to execute in the normal address space without being delayed, while copy-write subcommands operate independently in the shadow address space. This copying approach ensures atomicity for copy operations while allowing non-copy commands to proceed without time loss.
Data Source
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AI summary
Methods and devices are provided in which a controller of a storage device generates copy-read subcommands and copy-write subcommands of a copy command. The controller executes a blocking no-operation (NOP) command that spans a first storage address range of the copy-write subcommands in a first storage address space. The controller generates a mapping of the copy-write subcommands from the first storage address range, to mapped copy-write subcommands at a corresponding second storage address range in a second storage address space that is higher than a maximum storage address of the first storage address space. The controller executes the copy-read subcommands and the mapped copy-write subcommands. The mapped copy-write subcommands copy data for execution at the first storage address range.