Large-file support: Difference between revisions

Revision as of 06:55, 3 September 2019

Revision as of 04:05, 30 November 2019

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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]]' [[FAT32]] file system does not support files larger than 4 GiB−1; one has to use [[NTFS]] instead. (Some alternative file system implementations support an extension namedor [[FAT32+exFAT]], whichinstead. supports file sizes up to 256 GiB−1 in a mostly backward compatible way,<ref name="DRDOS_FAT+_R2"/> but this extension is not supported in mainstream operating systems so far.)

* To support binary compatibility with old [[Application software|applications]], operating system [[Application programming interface|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 [[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.