File System: Difference between revisions

Latest revision as of 09:50, 6 July 2025

File System is a crucial component of a computer's operating system that manages how data is stored and retrieved on storage devices. It provides a systematic way to organize, name, store, and access files, allowing users and applications to interact with data efficiently. File systems abstract the complexities of data storage, enabling higher-level operations that align with user needs and application requirements.

Background or History

The concept of a file system has its roots in the early days of computing, where data was initially managed through a series of physical devices and manual processes. The advent of magnetic tape in the 1950s allowed for primitive forms of data storage, leading to the first file systems that managed data in a linear fashion. These systems required meticulous organization, making navigation labor-intensive and error-prone.

With the introduction of hard disk drives in the 1960s, file systems evolved significantly. The ability to access data randomly, rather than sequentially, necessitated a more structured approach. Early file systems such as the File Allocation Table (FAT), which emerged in 1977, were foundational in establishing a hierarchy for data storage. FAT allowed users to store large files, including text and binaries, in a more manageable manner.

As computer technology advanced, so did the complexity and functionality of file systems. The 1980s and 1990s saw the rise of more sophisticated file systems such as the UNIX File System (UFS) and the High Performance File System (HPFS). These systems introduced features such as permissions, symbolic links, and improved storage efficiency, enhancing data integrity and user access control. Meanwhile, other file systems like NTFS emerged to meet the diverse needs of Windows operating systems.

Today, file systems continue to adapt to new technologies, including solid-state drives (SSDs) and cloud storage, which require innovative designs to maximize performance and reliability. The history of file systems reflects a continuous effort to balance efficiency, security, and user convenience.

Architecture or Design

The architecture of a file system consists of several components that work together to manage data. At its core, a file system organizes files through structures known as directories and hierarchies. This organizational scheme enables users to navigate and retrieve information efficiently. The architecture can generally be broken down into several layers, each serving distinct functions.

Metadata

Metadata is essential for the operation of a file system. It contains information about the files, such as their names, sizes, types, creation dates, and permissions. Metadata acts as a database for the file system, allowing it to efficiently locate and access files. For example, when a user searches for a file, the system accesses its metadata to quickly determine its location on the storage medium.

Data Structures

File systems employ various data structures to manage files and directories effectively. Common data structures include linked lists, B-trees, and hash tables. Each structure has its advantages and is chosen based on performance needs, the expected size of the file system, and the frequency of file access. For instance, B-trees provide efficient insertions, deletions, and searches, making them suitable for large file systems.

File Allocation

File allocation is a critical aspect of file system design, involving decisions about how space on a storage device is divided among files. Various allocation methods exist, including contiguous allocation, linked allocation, and indexed allocation. Contiguous allocation assigns a continuous sequence of blocks on the disk to a file, which offers excellent performance but can lead to fragmentation. Linked allocation resolves fragmentation by connecting scattered blocks with pointers, while indexed allocation utilizes an index block to keep track of the data blocks associated with a file.

File Access Methods

File systems also define how files can be accessed by users and applications. The primary access methods include sequential access, where data is read in a predetermined order, and random access, where data can be read or written in any order. The choice of access method can significantly affect the performance of data manipulation operations, such as reading or writing files.

Journaling and Logging

Modern file systems often implement journaling or logging techniques to enhance data integrity. These methods keep a log of changes before they are made to the main file system structure, ensuring that, in the event of a crash or power failure, the system can recover to a consistent state. By recording all operations, journaling helps prevent data corruption and loss. Popular file systems like ext4 (used in Linux) and NTFS (used in Windows) incorporate these techniques to enhance reliability.

Implementation or Applications

File systems are implemented in various contexts, from personal computers and servers to specialized devices such as printers and embedded systems. Each application may require different file system characteristics based on performance needs, size constraints, and specific functionalities.

Personal Computers

Desktop and laptop computers commonly utilize standard file systems, including NTFS for Windows, APFS for macOS, and ext4 for Linux. Each of these file systems offers features tailored to the user's needs, such as dynamic resizing, robust permissions, and support for large file sizes. The choice of file system can significantly affect the system's performance and the user's overall experience.

Servers and Data Centers

In server environments, file systems must handle large volumes of data while ensuring high performance and reliability. File systems like ZFS and GlusterFS are specifically designed for these tasks. ZFS includes features like snapshotting, data compression, and built-in RAID functionality, providing robust solutions for data integrity and management. GlusterFS, on the other hand, incorporates a distributed file system architecture, allowing for scalable storage solutions across multiple servers.

Embedded Systems

Embedded systems, which often feature limited storage and processing capabilities, utilize specialized file systems designed for efficiency and minimal overhead. Examples include FAT for simple devices or more complex systems like YAFFS (Yet Another Flash File System) for NAND flash. These file systems prioritize speed and reliability to accommodate the constraints of their environments.

Cloud Storage

Cloud storage services also rely on file systems to manage data distributed across multiple servers. These services may employ custom file systems or adapt existing ones to suit their architecture. For instance, Google File System (GFS) is designed specifically for Google's infrastructure, providing a fault-tolerant and distributed storage solution capable of handling petabytes of data.

Real-world Examples

Successful implementations of various file systems can be seen across numerous industries, demonstrating the flexibility and adaptability of file system technologies.

Ext4

The ext4 file system has become a standard choice among Linux distributions since its introduction in 2008. It offers significant improvements over its predecessor ext3, such as increased performance, support for larger file sizes, and advanced features like extents (contiguous blocks of storage), allowing for efficient management of space. Its reliability and robustness have made it a favored option for both servers and desktop environments.

NTFS

The NTFS file system, introduced with Windows NT in 1993, is known for its support of large volumes and files, enhanced security features, and journaling capabilities. NTFS has become the default file system for Windows operating systems, allowing users to create large partitions and securely manage file permissions and encryption. NTFS's adaptability has helped maintain its relevance for decades, supporting a wide range of applications from personal computing to enterprise-level solutions.

APFS

Apple File System (APFS) is designed for macOS and iOS devices, emphasizing efficiency and performance on solid-state storage. Introduced in 2017, APFS offers features like snapshots, which enable system restore points, and space-sharing capabilities that optimize storage usage. Its architecture provides enhanced speed and reliability, making it suitable for modern devices that require rapid data access.

ZFS

ZFS, a combined file system and logical volume manager, was developed by Sun Microsystems for Solaris in the mid-2000s. It highlights advanced data integrity through its use of checksums and snapshots, making it highly effective for enterprise data centers. ZFS's ability to manage vast amounts of data with built-in redundancy has made it a popular choice for organizations prioritizing data security and reliability.

Criticism or Limitations

Despite the advancements in file system technology, several criticisms and limitations have emerged, challenging their performance, usability, and scalability.

Fragmentation

File fragmentation occurs when a file is stored in non-contiguous blocks across a storage medium. This fragmentation can slow down read and write operations, as the file system must gather the scattered pieces of data. While some modern file systems implement techniques to minimize fragmentation, it can still be a concern, particularly in systems with limited resources.

Scalability Issues

As data continues to proliferate, many file systems face scalability challenges. Systems designed for smaller volumes may struggle to handle vast amounts of data or high transaction rates. While distributed file systems offer some scalability, they can also introduce complexity and potential points of failure, requiring careful management and oversight.

Compatibility

Different operating systems and file systems are often incompatible, leading to challenges in data sharing and accessibility. For instance, NTFS is not natively supported by Linux, complicating file transfers between Windows and Linux environments. Although tools exist to facilitate cross-platform compatibility, they often introduce performance penalties and may not support all features of the respective file systems.

Security Vulnerabilities

File systems are not immune to security threats. Vulnerabilities in file system implementations can result in data breaches, unauthorized access, and data loss. While modern file systems incorporate various security features, continuous advancements in hacking techniques necessitate ongoing improvements in file system security to protect sensitive information.

References

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-'''File System''' is a crucial component of a computer's operating system that controls how data is stored and retrieved on storage devices. It provides a way to organize data into a hierarchical structure, allowing users and applications to access and manage files efficiently. File systems also maintain metadata about files, manage disk space allocation, support complex data types, and enforce security and data integrity. This article will explore the history of file systems, their architecture, implementation, real-world examples, criticism, and limitations, as well as see also related topics.
+'''File System''' is a crucial component of a computer's operating system that manages how data is stored and retrieved on storage devices. It provides a systematic way to organize, name, store, and access files, allowing users and applications to interact with data efficiently. File systems abstract the complexities of data storage, enabling higher-level operations that align with user needs and application requirements.
-== History ==
+== Background or History ==
+The concept of a file system has its roots in the early days of computing, where data was initially managed through a series of physical devices and manual processes. The advent of magnetic tape in the 1950s allowed for primitive forms of data storage, leading to the first file systems that managed data in a linear fashion. These systems required meticulous organization, making navigation labor-intensive and error-prone.
-=== Early Developments ===
+With the introduction of hard disk drives in the 1960s, file systems evolved significantly. The ability to access data randomly, rather than sequentially, necessitated a more structured approach. Early file systems such as the File Allocation Table (FAT), which emerged in 1977, were foundational in establishing a hierarchy for data storage. FAT allowed users to store large files, including text and binaries, in a more manageable manner.
-The concept of file systems dates back to the early days of computing in the 1950s and 1960s. The first computers used simple storage systems, such as magnetic tapes, where data was accessed sequentially. As technology advanced, computers shifted towards more sophisticated storage mediums, including magnetic disks. The introduction of disk drives necessitated the development of more complex file management systems to provide efficient access.
-The initial file management systems were primarily designed for mainframe computers and used basic concepts such as directories and files, but they lacked advanced features. As personal computers became prevalent in the 1980s, operating systems like MS-DOS introduced more adaptable file systems suited for individual use. This era saw the development of FAT (File Allocation Table) file systems, which provided a straightforward mechanism for managing disk space.
+As computer technology advanced, so did the complexity and functionality of file systems. The 1980s and 1990s saw the rise of more sophisticated file systems such as the UNIX File System (UFS) and the High Performance File System (HPFS). These systems introduced features such as permissions, symbolic links, and improved storage efficiency, enhancing data integrity and user access control. Meanwhile, other file systems like NTFS emerged to meet the diverse needs of Windows operating systems.
-=== Advances in Technology ===
+Today, file systems continue to adapt to new technologies, including solid-state drives (SSDs) and cloud storage, which require innovative designs to maximize performance and reliability. The history of file systems reflects a continuous effort to balance efficiency, security, and user convenience.
-As computer applications grew more complex in the 1990s and 2000s, so did the requirements for file systems. The emergence of operating systems such as Windows NT, Linux, and macOS brought forth new file systems optimized for performance, reliability, and data security. Notable examples include NTFS (New Technology File System) for Windows, ext (Extended File System) for Linux, and HFS+ (Hierarchical File System Plus) for macOS.
-These file systems introduced several innovations, including support for larger file sizes and volumes, improved metadata handling, journaling for enhanced data integrity, and access permissions to manage security. The need for efficient storage solutions led to the introduction of network file systems and distributed file systems to facilitate collaborative work and remote access.
+== Architecture or Design ==
+The architecture of a file system consists of several components that work together to manage data. At its core, a file system organizes files through structures known as directories and hierarchies. This organizational scheme enables users to navigate and retrieve information efficiently. The architecture can generally be broken down into several layers, each serving distinct functions.
-== Architecture ==
+=== Metadata ===
+Metadata is essential for the operation of a file system. It contains information about the files, such as their names, sizes, types, creation dates, and permissions. Metadata acts as a database for the file system, allowing it to efficiently locate and access files. For example, when a user searches for a file, the system accesses its metadata to quickly determine its location on the storage medium.
-=== Structure of File Systems ===
+=== Data Structures ===
-At its core, a file system is structured around the concept of files and directories. A file serves as a unit of storage that can contain data, while a directory (or folder) acts as a container that can hold multiple files or subdirectories, organizing them hierarchically. This structure allows users to easily navigate and manage their data.
+File systems employ various data structures to manage files and directories effectively. Common data structures include linked lists, B-trees, and hash tables. Each structure has its advantages and is chosen based on performance needs, the expected size of the file system, and the frequency of file access. For instance, B-trees provide efficient insertions, deletions, and searches, making them suitable for large file systems.
-File systems maintain a metadata structure that contains information about files such as their names, sizes, types, creation and modification dates, and permissions. This metadata is crucial for appropriate file management and helps operating systems efficiently locate files without scanning the entire storage medium.
+=== File Allocation ===
+File allocation is a critical aspect of file system design, involving decisions about how space on a storage device is divided among files. Various allocation methods exist, including contiguous allocation, linked allocation, and indexed allocation. Contiguous allocation assigns a continuous sequence of blocks on the disk to a file, which offers excellent performance but can lead to fragmentation. Linked allocation resolves fragmentation by connecting scattered blocks with pointers, while indexed allocation utilizes an index block to keep track of the data blocks associated with a file.
-=== Allocation Methods ===
+=== File Access Methods ===
-File systems employ various allocation methods to manage how files occupy disk space. These methods fundamentally affect the performance of the system and determine how quickly data can be read from or written to the storage medium.
+File systems also define how files can be accessed by users and applications. The primary access methods include sequential access, where data is read in a predetermined order, and random access, where data can be read or written in any order. The choice of access method can significantly affect the performance of data manipulation operations, such as reading or writing files.
-The most common allocation methods include:
+=== Journaling and Logging ===
-* Contiguous allocation: This method allocates a single contiguous block of space for a file, which allows for efficient reading but can lead to fragmentation as files are created and deleted over time.
+Modern file systems often implement journaling or logging techniques to enhance data integrity. These methods keep a log of changes before they are made to the main file system structure, ensuring that, in the event of a crash or power failure, the system can recover to a consistent state. By recording all operations, journaling helps prevent data corruption and loss. Popular file systems like ext4 (used in Linux) and NTFS (used in Windows) incorporate these techniques to enhance reliability.
-* Linked allocation: In this method, a file is stored in scattered blocks across the disk, with each block containing a pointer to the next. This approach allows for more flexible space use but can result in slower access times.
-* Indexed allocation: Indexed allocation uses an index block to keep track of all the blocks belonging to a file. This method strikes a balance between the performance of contiguous allocation and the flexibility of linked allocation.
-Choosing the appropriate allocation method depends on the specific requirements and performance characteristics desired for a file system.
+== Implementation or Applications ==
+File systems are implemented in various contexts, from personal computers and servers to specialized devices such as printers and embedded systems. Each application may require different file system characteristics based on performance needs, size constraints, and specific functionalities.
-=== File System Interfaces ===
+=== Personal Computers ===
-File systems provide application programming interfaces (APIs) and command-line interfaces (CLIs) that allow users and applications to interact with the underlying structure. These interfaces include functions for creating, reading, writing, and deleting files as well as manipulating directories.
+Desktop and laptop computers commonly utilize standard file systems, including NTFS for Windows, APFS for macOS, and ext4 for Linux. Each of these file systems offers features tailored to the user's needs, such as dynamic resizing, robust permissions, and support for large file sizes. The choice of file system can significantly affect the system's performance and the user's overall experience.
-Modern file system interfaces also support advanced features such as file versioning, snapshots, and file compression. File systems may employ various interfaces based on their design, ranging from typical POSIX-compliant interfaces in UNIX-like operating systems to specialized interfaces for systems like NTFS and APFS (Apple File System).
+=== Servers and Data Centers ===
+In server environments, file systems must handle large volumes of data while ensuring high performance and reliability. File systems like ZFS and GlusterFS are specifically designed for these tasks. ZFS includes features like snapshotting, data compression, and built-in RAID functionality, providing robust solutions for data integrity and management. GlusterFS, on the other hand, incorporates a distributed file system architecture, allowing for scalable storage solutions across multiple servers.
-== Implementation ==
+=== Embedded Systems ===
+Embedded systems, which often feature limited storage and processing capabilities, utilize specialized file systems designed for efficiency and minimal overhead. Examples include FAT for simple devices or more complex systems like YAFFS (Yet Another Flash File System) for NAND flash. These file systems prioritize speed and reliability to accommodate the constraints of their environments.
-=== Types of File Systems ===
+=== Cloud Storage ===
-Various types of file systems have been developed to meet the unique needs of different environments and applications. Some of the prominent types include:
+Cloud storage services also rely on file systems to manage data distributed across multiple servers. These services may employ custom file systems or adapt existing ones to suit their architecture. For instance, Google File System (GFS) is designed specifically for Google's infrastructure, providing a fault-tolerant and distributed storage solution capable of handling petabytes of data.
-* Local file systems: These are designed for use on a single machine, facilitating storage access locally. Common examples include FAT32, NTFS, ext4, and APFS.
-* Network file systems: These enable sharing and accessing files across a network. Examples include NFS (Network File System), SMB (Server Message Block), and FTP (File Transfer Protocol).
-* Distributed file systems: Distributed file systems ensure that files are available across multiple networked computers. They efficiently handle data replication and provide fault tolerance. Examples comprise Google File System and Hadoop Distributed File System (HDFS).
-* Flash file systems: Optimized for solid-state drives (SSDs) and flash memory, these file systems address specific challenges posed by these fast and volatile storage mediums. Examples include YAFFS (Yet Another Flash File System) and JFFS2 (Journaling Flash File System 2).
-Choosing the appropriate file system type depends on several factors, including the intended workload, data access patterns, and hardware specifics.
-=== Security Features ===
-Security is a paramount consideration in file system implementation. Modern file systems incorporate various security features to protect data from unauthorized access and corruption. These features include:
-* Access controls: File systems often implement permission schemes, such as read, write, and execute permissions, enabling the specification of who can access or manipulate specific files and directories.
-* Encryption: Many file systems support encryption techniques that protect data integrity and confidentiality during storage and transmission. Encryption can be applied at the file level or at the volume level.
-* Journaling: Journaling file systems maintain a log of changes before applying them, which enhances data integrity and makes recovery more manageable in case of crashes or power failures.
-* Backup and recovery mechanisms: Effective backup strategies are critical in safeguarding data. Many file systems support native backup and recovery features that facilitate regular data snapshots and point-in-time restores.
-These features reflect the evolving landscape of file system security, as threats to data integrity continue to grow.
 == Real-world Examples ==
+Successful implementations of various file systems can be seen across numerous industries, demonstrating the flexibility and adaptability of file system technologies.
-=== FAT32 ===
+=== Ext4 ===
-FAT32 (File Allocation Table 32) is a file system introduced by Microsoft in the 1990s and is an extension of the original FAT system. It remains widely used due to its simplicity and compatibility across multiple operating systems, making it suitable for portable storage devices like USB flash drives and external hard drives. However, FAT32 has limits, including a maximum file size of 4 GB and a maximum volume size of 8 TB.
+The ext4 file system has become a standard choice among Linux distributions since its introduction in 2008. It offers significant improvements over its predecessor ext3, such as increased performance, support for larger file sizes, and advanced features like extents (contiguous blocks of storage), allowing for efficient management of space. Its reliability and robustness have made it a favored option for both servers and desktop environments.
 === NTFS ===
-NTFS (New Technology File System) is the successor to FAT and provides numerous advanced features, including support for larger file sizes, file permissions, encryption, and recovery logging. It is the standard file system for modern Windows operating systems. NTFS is designed for reliability and security, making it the preferred file system for internal drives and large-volume storage.
+The NTFS file system, introduced with Windows NT in 1993, is known for its support of large volumes and files, enhanced security features, and journaling capabilities. NTFS has become the default file system for Windows operating systems, allowing users to create large partitions and securely manage file permissions and encryption. NTFS's adaptability has helped maintain its relevance for decades, supporting a wide range of applications from personal computing to enterprise-level solutions.
-=== ext4 ===
-ext4 (Fourth Extended File System) is a widely used file system in Linux environments. It offers enhancements over its predecessors, ext2 and ext3, such as support for larger file sizes, improved performance, and better journaling mechanisms. ext4 is characterized by its ability to handle large volumes efficiently while maintaining data integrity, making it a popular choice for both desktop and server installations.
 === APFS ===
-APFS (Apple File System) is the file system developed by Apple Inc. for macOS, iOS, and other Apple devices. Announcement of APFS came as part of macOS High Sierra in 2017, reflecting a shift towards modern storage solutions. APFS features include snapshots, encryption, and enhanced performance for SSDs. Its design is specifically tailored to address the requirements of Apple’s ecosystem, emphasizing efficiency and security.
+Apple File System (APFS) is designed for macOS and iOS devices, emphasizing efficiency and performance on solid-state storage. Introduced in 2017, APFS offers features like snapshots, which enable system restore points, and space-sharing capabilities that optimize storage usage. Its architecture provides enhanced speed and reliability, making it suitable for modern devices that require rapid data access.
-=== HDFS ===
+=== ZFS ===
-Hadoop Distributed File System (HDFS) is a distributed file system designed to handle large datasets across clusters of commodity hardware. It is a fundamental component of Apache Hadoop and is optimized for high throughput and fault tolerance. HDFS supports data replication and ensures availability even in the case of hardware failures. It has become a critical component in big data applications and analytics.
+ZFS, a combined file system and logical volume manager, was developed by Sun Microsystems for Solaris in the mid-2000s. It highlights advanced data integrity through its use of checksums and snapshots, making it highly effective for enterprise data centers. ZFS's ability to manage vast amounts of data with built-in redundancy has made it a popular choice for organizations prioritizing data security and reliability.
-== Criticism ==
+== Criticism or Limitations ==
+Despite the advancements in file system technology, several criticisms and limitations have emerged, challenging their performance, usability, and scalability.
-=== Performance Limitations ===
+=== Fragmentation ===
-Despite their advantages, many traditional file systems face performance bottlenecks. As file systems grow, managing metadata and the allocation of storage can become increasingly inefficient. Fragmentation can lead to degraded read/write speeds and increased latency, particularly in systems dealing with large volumes of transactions or data management.
+File fragmentation occurs when a file is stored in non-contiguous blocks across a storage medium. This fragmentation can slow down read and write operations, as the file system must gather the scattered pieces of data. While some modern file systems implement techniques to minimize fragmentation, it can still be a concern, particularly in systems with limited resources.
-=== Complexity and Overhead ===
+=== Scalability Issues ===
-The complexity of modern file systems introduces overhead that can impact performance. Features such as journaling, encryption, and advanced access control mechanisms require additional processing power and can lead to slower access times. In environments where high-speed access is critical, the overhead associated with these features can be a significant drawback.
+As data continues to proliferate, many file systems face scalability challenges. Systems designed for smaller volumes may struggle to handle vast amounts of data or high transaction rates. While distributed file systems offer some scalability, they can also introduce complexity and potential points of failure, requiring careful management and oversight.
-=== Vendor Lock-In ===
+=== Compatibility ===
-Different operating systems often rely on proprietary file systems, which can pose challenges in cross-platform compatibility. Organizations may find it difficult to migrate data between different systems, leading to vendor lock-in. This situation can inhibit seamless collaboration across diverse technical ecosystems, complicating data sharing and integration efforts.
+Different operating systems and file systems are often incompatible, leading to challenges in data sharing and accessibility. For instance, NTFS is not natively supported by Linux, complicating file transfers between Windows and Linux environments. Although tools exist to facilitate cross-platform compatibility, they often introduce performance penalties and may not support all features of the respective file systems.
-=== Scalability Issues ===
+=== Security Vulnerabilities ===
-Some file systems, especially legacy systems, may struggle with scalability as data volumes increase. Limitations on file sizes, total number of files, and directory structures can hinder operational growth for organizations. As businesses increasingly rely on larger datasets, such constraints become more problematic, necessitating the adoption of more flexible, scalable solutions.
+File systems are not immune to security threats. Vulnerabilities in file system implementations can result in data breaches, unauthorized access, and data loss. While modern file systems incorporate various security features, continuous advancements in hacking techniques necessitate ongoing improvements in file system security to protect sensitive information.
 == See also ==
-* [[Data Storage]]
+* [[Data storage]]
-* [[File Compression]]
+* [[Computer operating system]]
-* [[Network File System]]
+* [[Solid-state drive]]
-* [[Operating System]]
+* [[NTFS]]
-* [[Solid State Drive]]
+* [[FAT]]
-* [[Data Backup]]
+* [[Distributed file system]]
 == References ==
-* [https://www.microsoft.com/en-us/windows/ntfs NTFS - Microsoft]
+* [https://www.microsoft.com/en-us/windows/nt File System Overview - Microsoft]
-* [https://www.linux.org/pages/faq/ext4.html ext4 - Linux)
+* [https://www.kernel.org/doc/html/latest/filesystems/index.html Linux Filesystem Documentation]
-* [https://www.apple.com/apfs/ APFS - Apple]
+* [https://www.freebsd.org/doc/handbook/Filesystem.html FreeBSD Handbook - File Systems]
-* [https://hadoop.apache.org/docs/stable/hadoop-project-dist/hadoop-hdfs/HdfsUserGuide.html HDFS - Apache]
+* [https://www.apple.com/apfs/ Apple File System - Apple]
+* [https://zfs.wiki.kernel.org/index.php/Main_Page ZFS Wiki]
+* [https://www.gnu.org/software/gcrypt/manual/html_node/Data-Storage.html GNU Privacy Guard - File Storage]
 [[Category:File systems]]
 [[Category:Data storage]]
 [[Category:Computer science]]