Large-file support: Difference between revisions

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{{Lead too short|date=February 2020}}

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{{Use list-defined references|date=January 2022}}

'''Large-file support''' ('''LFS''') is the term frequently applied to the ability to create files larger than either 2 or 4 [[Gibibyte|GiB]] on [[32-bit]] [[filesystem]]s.

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

* The change to 64-bit file sizes frequently required incompatible changes to file system layout, which meant that large-file support sometimes necessitated a file system change. For example, [[Microsoft Windows]]'the [[FAT32]] file system does not support files larger than 4&nbsp;GiB−1 (with older applications even only 2&nbsp;GiB−1); onethe hasvariant [[FAT32+]] does support larger files (up to 256&nbsp;GiB−1), but (so far) is only supported in some versions of [[DR-DOS]],<ref name="Kuhnt-Georgiev-Davis_2007_FAT+"/><ref name="Kuhnt_2011_EDR"/> so users of [[Microsoft Windows]] have to use [[NTFS]] or [[exFAT]] instead.

* To support binary compatibility with old [[application software|application]]s, operating system [[application programming interface|interface]]s 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 [[porting|portable]] code that makes use of LFS where possible, [[C standard library]] authors devised mechanisms that, depending on [[C preprocessor|preprocessor]] constants, transparently redefined the functions to the 64-bit large-file aware ones.

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The usage of the large-file API in 32-bit programs had been incomplete for a long time. An analysis did show in 2002 that many base libraries of operating systems were still shipped without large-file support thereby limiting applications using them.<ref name="Largefile_Distros"/> The much-used [[zlib]] library started to support 64-bit large-files on 32-bit platform not before 2006.<ref name="ZLib_Changelog"/>

The problem disappeared slowly with PCPCs and workstations moving completely to [[64-bit computing]]. Microsoft Windows Server 2008 has been the last server version to be shipped in 32-bit.<ref name="Kolokythas_2007"/> [[Red Hat Enterprise Linux#Red Hat Enterprise Linux 7.x|Redhat Enterprise Linux 7]] was published in 2014 only as a 64-bit operating system.<ref name="RHEL_2014_32bit"/> Ubuntu Linux stopped delivering a 32-bit variant in 2019.<ref name="Cooke_2019_32bit"/> Nvidia stopped developingto develop 32-bit drivers in 2018 and they stopped deliveringdeliver updates after January 2019.<ref name="Addams_2018_Nvidia"/> Apple stopped developing 32-bit Mac OS versions in 2018 delivering [[macOS Mojave]] only as a 64-bit operating system.<ref name="Silver_2018_Apple"/> There is noThe [[End-of-life (product)|end-of-life]] known for Windows 10 has been set to 2025 on the desktop which is related to the latest upgrades from old systems like Windows 7 & Windows 8 in January 2020 as some of those system ran on old computers built on the i386 architecture.<ref name="Microsoft_Windows7"/> [[Windows 11]] however will ship only as a 64-bit operating system since its first version in 2021.

A similar development can be seen in the mobile area. Google required to support 64-bit versions of applications in their app store by August 2019,<ref name="Sebayang_2019_Android"/> which allows to discontinue 32-bit support for [[Android (operating system)|Android]] later.<ref name="MW_2014"/> The shift towards 64-bit started in 2014 when all new processors were designed to a 64-bit architecture and [[Android Lollipop|Android 5]] ("Lollipop") was published in that year providing a fitting 64-bit variant of the operating system.<ref name="Android_User_2014"/><ref name="MW_2014"/> Apple had made shift in the year before starting to produce the 64-Bit [[Apple A7]] by 2013. Google started to deliver the development environment for Linux only in 64-bit by 2015.<ref name="APT_2015"/> In May 2019 the share of Android versions below 5 had fallen to ten percent.<ref name="Tenzer_2019"/> As [[Mobile app|app]] developers concentrate on a single [[executable|compilation]] variant, many manufacturers started to require Android 5 as the minimum version by mid 2019, for example Niantic.<ref name="Favero_2019"/> Subsequently the 32-bit versions were hard to get.<ref name="Reddit_2019"/>

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* [[RF64]] – 64-bit support for [[Broadcast Wave Format|BWF WAV]] audio files

* [[Comparison of text editors#Extra features|Comparison of large-file support in text editors]]

* [[FAT32+]]<ref name="FAT+"/>

* [[File size]]

* [[File spanning]]

* [[Long filename support]] (LFN)

* [[Year 2038 problem]]

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<ref name="Solaris_1996">{{cite web |author=Solaris OS group |date=March 1996 |title=Large Files in Solaris: A White Paper |publisher=[[Sun Microsystems]] |url=http://www.sun.com/software/whitepapers/wp-largefiles/largefiles.pdf |archive-url=https://web.archive.org/web/20070228204423/http://www.sun.com/software/whitepapers/wp-largefiles/largefiles.pdf |archive-date=2007-02-28}}</ref>

<ref name="Unix_1996_LFS">{{cite web |date=1996-08-14 |title=Adding Large File Support to the Single UNIX Specification |publisher=X/Open Base Working Group |url=http://opengroup.org/platform/lfs.html |access-date=2006-09-10}}</ref>

<ref name="FATKuhnt-Georgiev-Davis_2007_FAT+">{{cite web |title=FAT+ draft revision 2 |author-first1=Udo |author-last1=Kuhnt |author-first2=Luchezar I. |author-last2=Georgiev |author-first3=Jeremy |author-last3=Davis |date=2007 |format=FATPLUS.TXT |edition=2 |url=http://www.fdos.org/kernel/fatplus.txt |access-date=2015-08-05 |url-status=dead |archive-url=https://web.archive.org/web/20150219123449/http://www.fdos.org/kernel/fatplus.txt |archive-date=2015-02-19}}</ref>

<ref name="Kuhnt_2011_EDR">{{cite web |title=DR-DOS/OpenDOS Enhancement Project |author-first=Udo |author-last=Kuhnt |date=2011-07-21 |url=http://www.drdosprojects.de/ |access-date=2015-04-20 |url-status=dead |archive-url=https://web.archive.org/web/20160604014846/http://www.drdosprojects.de/ |archive-date=2016-06-04}}</ref>

<ref name="Largefile_Distros">http://ac-archive.sourceforge.net/largefile/distros.html</ref>

<ref name="ZLib_ChangelogLargefile_Distros">{{cite web |url=https://wwwac-archive.zlibsourceforge.net/ChangeLoglargefile/distros.txthtml |title=Distro Makers |date=2002-01-13}}</ref>

<ref name="ZLib_Changelog">{{Cite web| title=ChangeLog file for zlib | url=https://www.zlib.net/ChangeLog.txt | archive-url=https://web.archive.org/web/20031218063837/http://zlib.net:80/ChangeLog.txt | archive-date=2003-12-18}}</ref>

<ref name="Kolokythas_2007">{{cite web |title=Windows Server 2008: Microsofts letztes 32-Bit-Betriebssystem für Server |language=de |author-first=Panagiotis |author-last=Kolokythas |publisher=[[PC Welt]] |date=2007-05-28 |url=https://www.pcwelt.de/news/Windows-Server-2008-Microsofts-letztes-32-Bit-Betriebssystem-fuer-Server-334946.html}}</ref>

<ref name="RHEL_2014_32bit">{{cite web |title=Are 32-bit applications supported in RHEL 7 or later releases? |publisher=[[Red Hat]] |date=February 2014 |url=https://access.redhat.com/solutions/509373}}</ref>

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<ref name="Reddit_2019">{{cite web |title=Why is 32bit 0.159.0 version apk still not available? |publisher=Reddit |work=TheSilphRoad/ |date=December 2019 |url=https://www.reddit.com/r/TheSilphRoad/comments/dm6c51/why_is_32bit_01590_version_apk_still_not_available/}}</ref>

<ref name="Microsoft_2019_CRT">{{cite web |url=https://docs.microsoft.com/en-us/cpp/c-runtime-library/reference/findfirst-functions?view=vs-2019 |title=C Run-time library (CRT) reference: findfirst |publisher=[[Microsoft]] |access-date=2020-02-17}}</ref>

<ref name="lfs_2015">{{cite web |url=https://users.suse.com/~aj/linux_lfs.html |title=Large File Support in Linux |publisher=[[SUSE S.A.|SuSE GmbH]] |date=2015-02-15 |author-first=Andreas |author-last=Jaeger}}</ref>

<ref name="Linux_stat.h">linux/bits/stat.h: /* Note stat64 has the same shape as stat for x86-64. */</ref>

<ref name="Rutter_2020_inode">{{cite web |url=https://www.mjr19.org.uk/sw/inodes64.html |title=The 64 bit inode problem |author-first=M. J. |author-last=Rutter |access-date=2020-02-10}}</ref>

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==External links==

* {{cite web |author-first=Andreas |author-last=Jaeger |date=2005-02-15 |title=Large File Support in Linux |publisher=[[SUSE S.A.|SuSE GmbH]] |url=http://www.suse.de/~aj/linux_lfs.html |access-date=2006-09-10}}

[[Category:Computer file systems]]