Page Table Metadata Protection via Bitwise Nesting

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Solution Overview

Problem

Existing data storage systems lack efficient mechanisms to protect page-level metadata, leading to potential metadata corruption and inconsistency, especially in component-level storage systems where SCSI-level protection information is not suitable.

Innovation Solution

Incorporating protection information into page tables, stored bitwise in sequential locations, to determine metadata reliability and consistency, without increasing page table size, using a processor and memory with a storage controller to compare protection data and identify inconsistencies.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If protection information is added to page tables to protect metadata, then metadata reliability is improved, but page table size increases

Engineering Contradiction:

Improvemetadata reliabilityVSAvoidpage table size

Core Design Contradiction:

ReliabilityVSVolume of stationary object

Solution Approach 1:

The protection information is nested within the existing page table structure by utilizing unused or spare bits within the page table entries. This allows metadata protection to be embedded without requiring additional storage space outside the page table, thus improving metadata reliability while maintaining the original page table size.

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

Protection information is applied selectively to specific page table entries rather than uniformly to all entries. This local application of protection allows the system to focus redundancy where most needed while minimizing the overall impact on page table structure and size, resolving the contradiction between reliability improvement and size increase.

Inventive Principle:

Principle #3Local quality

2Reliability

If SCSI-level protection information is used in component-level storage systems, then protection coverage is improved, but compatibility and suitability deteriorate

Engineering Contradiction:

Improveprotection coverageVSAvoidsuitability for component-level systems

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The protection mechanism is adapted from SCSI-block level to component-level by changing the granularity and scope of protection parameters. Instead of protecting at the block level as in SCSI systems, the invention implements protection at the component level, matching the organizational structure of modern storage systems and improving suitability while maintaining comprehensive coverage.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

Rather than adapting component-level systems to use SCSI-level protection schemes, the invention inverts the approach by developing protection mechanisms specifically designed for component-level architecture. This reversal creates a native protection solution that is inherently compatible with component-level storage systems while providing adequate protection coverage.

Inventive Principle:

Principle #13The other way round (Inversion)

Data Source

PatentUS8990542B2Efficient metadata protection system for data storage

Publication Date: 2015.03.24 SEAGATE CLOUD SYSTEMS INC

AI summary

A method for protecting page-level metadata in a storage system is provided. The method includes providing in a page table first protection data, receiving a command to read data from a page of the storage system corresponding to the page table, and comparing first protection data to second protection data. If the first protection data is different than the second protection data, then the method includes identifying third protection data in the storage system and comparing the third protection data to the first protection data. If the third protection data is different than the first protection data, then the method includes determining that the page-level metadata is inconsistent.