In-Place Storage Pool Extent Conversion via Metadata Reordering

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing processes for converting extent sizes in storage pools are time-consuming and inefficient, requiring data migration to another storage pool, which consumes additional resources and causes performance delays.

Innovation Solution

A computer-implemented method that reorders volume extents in the existing storage pool to align with the intended storage pool's boundaries, allowing conversion of rank extent sizes without data migration, using temporary pauses and new structure population in volume segment tables to maintain data in place during conversion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional data migration process is used to convert extent sizes, then extent size conversion can be achieved, but additional storage resources are consumed and processing bandwidth is required

Engineering Contradiction:

Improveextent size conversion capabilityVSAvoidstorage resource consumption

Core Design Contradiction:

Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The patent extracts the data migration step from the extent size conversion process, allowing conversion to occur in-place without removing data to external storage. The conversion is performed by modifying metadata structures (extent pool descriptors, volume descriptors) directly within the existing storage pool, eliminating the need for additional storage resources.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces metadata structures (extent pool descriptors, volume descriptors, extent allocation tables) as intermediaries that manage the conversion process. These metadata structures enable the system to track and manage extent allocations during conversion without requiring physical data movement, serving as a mediator between the storage hardware and the conversion logic.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If conventional data migration process is used to convert extent sizes, then extent size conversion can be achieved, but time to physically copy all data is required

Engineering Contradiction:

Improveextent size conversion capabilityVSAvoiddata conversion time

Core Design Contradiction:

Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent performs preliminary actions by first identifying and marking extents for conversion in the metadata structures before actual conversion occurs. The extent pool descriptor is updated in advance to reflect the new extent size, and volume descriptors are prepared to accommodate the conversion, allowing the actual data blocks to be converted in-place without time-consuming migration.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent replaces the mechanical data copying process with a metadata-driven conversion approach. Instead of physically moving data blocks between storage locations, the system uses software-based metadata updates to reorganize extent allocations and update mapping structures, significantly reducing conversion time.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Adaptability or versatility

If data is migrated to another storage pool for conversion, then extent size conversion can be performed, but network traffic increases and performance delays occur

Engineering Contradiction:

Improveextent size conversion capabilityVSAvoidoperational efficiency

Core Design Contradiction:

Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent extracts the data movement operation from the conversion process entirely, performing conversion in-place within the existing storage pool. This eliminates network traffic associated with data migration and prevents performance delays caused by I/O operations during conversion, maintaining high operational efficiency.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The storage pool performs the conversion operation on itself using its existing resources and metadata structures. The extent pool descriptor and volume descriptors within the storage pool are updated to reflect the new extent size, and the conversion is accomplished through self-contained metadata modifications without requiring external storage pool involvement.

Inventive Principle:

Principle #25Self-service

Data Source

PatentUS11314435B2Converting small extent storage pools into large extent storage pools in place

Publication Date: 2022.04.26 INTERNATIONAL BUSINESS MACHINE CORPORATION

AI summary

A computer-implemented method, according to one approach, is for converting an existing storage pool into an intended storage pool in place. The computer-implemented method includes: reordering volume extents in the existing storage pool such that physical rank extents of the volumes align with boundaries between rank extents of the intended storage pool. The ranks in the existing storage pool are also converted from first rank extent sizes to second rank extent sizes. Moreover, in response to converting the ranks in the existing storage pool, for each of the volumes: a temporary pause/lock is performed on a volume segment table (VST) entry which corresponds to the given volume, and the VST entry is populated with a new structure which corresponds to the respective second rank extent size.