PTDDC Chain Virtual Disk Storage for NTFS GPT Header Support
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current disk drive systems face limitations in daisy-chaining, logical concatenation, and supporting spatially diverse data structures, leading to high interconnect costs and inefficiencies in storage array configurations, particularly with Microsoft NTFS file systems that require GPT headers and tables at both ends of the LBA address space, which is challenging for PTDDC chains with varying physical storage.
Innovation Solution
The implementation of a hardware mapping data structure within the PTDDC that allows specific LBA ranges to be mapped to actual storage within a PTDDC chain, incorporating phantom storage and non-volatile memory to ensure seamless operation of NTFS and other file systems, even when physical storage is not available at the end of the logical chain, by using RESERVED.SYS files and partitions to manage virtual storage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If PTDDC chains are used to extend storage capacity, then storage capacity is increased, but interconnect costs increase
Solution Approach 1:
The patent merges multiple physical disk drives into a single logical disk drive through the PTDDC chain architecture. The host computer system sees one logical drive with a unified LBA address space, while the controller combines I/O operations across multiple physical drives. This merging reduces the number of individual drive connections and management overhead, addressing the interconnect cost issue while maintaining extended storage capacity.
Solution Approach 2:
The PTDDC controller serves multiple functions: it acts as a disk drive interface to the host, a daisy-chain controller for connecting multiple drives, and a mapping controller for LBA translation. This multi-functionality consolidates what would otherwise require separate components, reducing overall system complexity and interconnect requirements while enabling storage extension.
2Reliability
If GPT headers and tables are placed at both ends of LBA address space for NTFS, then file system reliability is improved, but storage efficiency deteriorates when physical storage is unavailable at chain ends
Solution Approach 1:
The PTDDC controller acts as an intermediary that translates host LBA addresses to physical drive addresses. It maintains mapping tables that track which LBAs map to which physical drives, enabling the system to present a continuous LBA address space to the host even when physical drives are distributed across multiple devices. This intermediary function allows NTFS to operate normally without requiring physical storage at both ends of the logical address space.
Solution Approach 2:
The patent segments the logical LBA address space across multiple physical drives through the PTDDC chain. The controller divides the continuous LBA space into segments that map to different physical drives in the daisy-chain. This segmentation allows the system to maintain the reliability benefits of having GPT structures at both ends of the logical address space while distributing physical storage efficiently across available drives.
3Adaptability or versatility
If PTDDC chains present larger logical capacities than physical storage, then storage flexibility is improved, but system complexity increases
Solution Approach 1:
The PTDDC controller creates a virtual copy of the storage address space that differs from the physical layout. It maintains a mapping table that copies logical LBA addresses to physical drive addresses, allowing the host to interact with a simplified logical view while the controller handles the complexity of physical distribution. This copying approach enables storage flexibility without requiring the host to understand or manage the underlying physical complexity.
Data Source
AI summary
A file system extension (FSE) system and method that permits an on-disk-structure (ODS) incorporating spatially diverse data (SDD) to be stored on a daisy-chain of multiple SATA disk drive storage elements (DSE) that are coupled together with one or more pass-thru disk drive controllers (PTDDC) is disclosed. The PTDDC chain appears as a single logical disk drive to a host computer system (HCS) via a host bus adapter (HBA) or pass-thru input (PTI) port. The PTDDC chain may appear to the HCS as virtual disk storage (VDS) that is larger than the actual physical disk storage (PDS) contained within the DSEs. The PTDDC chain is configured to map the SDD to portions of the DSE that are actually present within the VDS and thus allow critical portions of the ODS to reside on the PTDDC chain with transparent access by an operating system running on the HCS.