Windows File Systems

This section provides comprehensive documentation on the file systems supported by Microsoft Windows. Understanding these file systems is crucial for managing data, optimizing performance, and ensuring data integrity within the Windows operating system.

Overview of Windows File Systems

Windows supports several file systems, each with its own set of features, limitations, and use cases. The primary file systems encountered are:

• NTFS (New Technology File System): The default and most advanced file system for Windows. It offers robust features like journaling, security permissions, file compression, encryption, and support for large files and volumes.
• FAT (File Allocation Table) variants (FAT32, exFAT): Older but still widely used file systems, particularly for removable media like USB drives and SD cards due to broad compatibility. FAT32 has limitations on individual file size and volume size. exFAT addresses many of these limitations, making it suitable for larger flash drives.
• ReFS (Resilient File System): A modern file system designed for high data availability and integrity, primarily targeted at large-scale storage solutions and servers. ReFS includes features like data scrubbing and integrity checksums.

NTFS: The Core File System

NTFS is the backbone of Windows file storage. Its key features include:

• Journaling: Records file system changes before they are committed, allowing for quick recovery in case of system crashes or power failures.
• Access Control Lists (ACLs): Provides granular control over file and folder permissions for users and groups.
• File and Folder Compression: Allows for on-the-fly compression to save disk space.
• Encryption File System (EFS): Enables users to encrypt files and folders for enhanced security.
• Hard Links and Symbolic Links: Advanced features for file system organization and management.
• Support for Large Files and Volumes: Handles very large files and partitions, far exceeding the limits of FAT32.

NTFS Internals

Key NTFS structures include:

• Master File Table (MFT): A database containing records for every file and directory on the volume.
• Attribute Lists: Stores metadata about files, such as name, size, timestamps, and data content (or pointers to data).
• Bitmap: Tracks the allocation status of clusters on the volume.

FAT Variants: Compatibility and Simplicity

FAT file systems are known for their simplicity and broad compatibility across different operating systems and devices.

• FAT32: Limited to a maximum file size of 4GB and a maximum volume size of 2TB (though Windows limits partition creation to 32GB).
• exFAT: Designed to overcome FAT32's limitations, supporting much larger files and volumes. It's often used for SD cards and USB flash drives.

ReFS: Resilience and Data Integrity

ReFS is built to address the challenges of data integrity in modern storage environments:

• Integrity Streams: ReFS can detect and automatically correct data corruption for files that use this feature.
• Storage Spaces Integration: Works closely with Storage Spaces to provide resilience against drive failures.
• Scrubbing: Periodically scans the file system to detect latent corruption.
• Copy-on-Write: Data is written to a new location rather than overwriting existing data, protecting against partial writes.