Large file support, often abberviated to LFS, is the term frequently applied to the support for files larger than 2 GB on 32-bit operating systems. A gibibyte is a unit of information or computer storage. ... In computing, an operating system (OS) is the system software responsible for the direct control and management of hardware and basic system operations. ...

Traditionally, many operating systems and their underlying file system implementations used 32-bit integers to represent file sizes and positions. Consequently no file could be larger than 2³² bytes (4 GB). The problem was exacerbated by treating the sizes as signed numbers, which further lowered the limit to 2³¹ bytes (2 GB). Files larger than 2 GB, too large for 32-bit operating systems to handle, came to be known as large files. In computing, a file system is a method for storing and organizing computer files and the data they contain to make it easy to find and access them. ... 32-bit is a term applied to processors, and computer architectures which manipulate the address and data in 32-bit chunks. ... The integers consist of the positive natural numbers (1, 2, 3, …), their negatives (−1, −2, −3, ...) and the number zero. ... A file in a computer system is a stream (sequence) of bits stored as a single unit, typically in a file system on disk or magnetic tape. ... A negative number is a number that is less than zero, such as −3. ...

While the 2 GB limit was quite acceptable at a time when disks were smaller, the general increase in storage capacity combined with more intense server and desktop file usage, especially for database and multimedia files, lead to intense pressure for OS vendors to remove the limitation. Typical hard drives of the mid-1990s. ... A database is an organized collection of data. ... Multimedia is the use of several different media to convey information (text, audio, graphics, animation, video, and interactivity). ...

Eventually vendors responded by switching to 64-bit numbers to represent file sizes, thus introducing large file support. (Merely ensuring the sizes were treated as unsigned numbers would not have been sufficient, except as a stop-gap measure, because it would only up the limit from 2 GB to 4 GB, which would not make a difference to most users.) It is worth noting that 64-bit operating systems, such as Tru64, never had the 32-bit limit to begin with, and hence needed no additional "large file support". In computing, a 64-bit component is one in which data are processed or stored in 64-bit units (words). ... A negative number is a number that is less than zero, such as −3. ... Tru64 is HPs (formerly Compaq; formerly DEC) 64-bit UNIX for the Alpha AXP platform. ...

This switch caused deployment issues and required design choices the consequences of which can still be seen:

• The change to 64-bit file sizes frequently required incompatible changes to file system layout, which means that large file support sometimes necessitated a file system change. For example, Windows's FAT32 file system does not support files larger than 4 GB; one has to use NTFS instead.
• To support binary compatibility with old applications, operating system interfaces had to retain their use of 32-bit file sizes and new interfaces had to be designed specifically for large file support.
• To support writing portable code that makes use of LFS where possible, C standard library authors devised mechanisms that, depending on preprocessor constants, transparently redefined the functions to the 64-bit large file aware ones.
• Many old interfaces, especially C-based ones, explicitly specified argument types in a way that did not allow straightforward nor transparent transition to 64-bit types. For example, the C functions fseek and ftell operate on file positions of type long int, which is typically 32 bits wide on 32-bit architecture, and cannot be made larger without sacrificing backward compatibility. (This was resolved by introducing new functions fseeko and ftello.)
• The above efforts notwithstanding, all applications had to be recompiled to make them LFS-aware. The resulting binaries were typically not runnable on older releases of the same operating system. This was, and to some extent still remains, a problem for some application vendors.

Because of these transition issues many present-day applications still do not support large files. 1. ... File Allocation Table (FAT) is a file system that was developed for MS-DOS and used in consumer versions of Microsoft Windows up to and including Windows Me. ... NTFS or New Technology File System is the standard file system of Windows NT and its descendants Windows 2000, Windows XP and Windows Server 2003. ... ... BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB... API with 3 clients, using the Unified Modeling Language notation An application programming interface (API) is a set of definitions of the ways one piece of computer software communicates with another. ... Portable communications devices refer to hand-held or wearable devices. ... The C standard library is a now-standardised collection of header files and library routines used to implement common operations, such as input/output and string handling, in the C programming language. ... The C preprocessor is a preprocessor for the C programming language. ... The C Programming Language, Brian Kernighan and Dennis Ritchie, the original edition that served for many years as an informal specification of the language The C programming language is a standardized imperative computer programming language developed in the early 1970s by Ken Thompson and Dennis Ritchie for use on the... COMPILE COMPILE was a Japanese Video Games company that produced various memorable games for various systems. ... An executable or executable file, in computer science, is a file whose contents are meant to be interpreted as a program by a computer. ...

External links

• White Paper "Adding Large File Support to the Single UNIX® Specification"
• Large File Support in Linux
• How to access files larger than 2GB in your program on Linux/x86