“The Unix98 standard requires largefile support, and many of the latest operating systems provide it. However, some systems still chose not to make it the default, resulting in two models: Some parts of the system use the traditional 32bit off_t, while others are compiled with a largefile 64bit off_t. Mixing libraries and plugins is not a good idea.” Read the article at Freshmeat. On another interesting technical reading, you will find “Understanding the Linux Virtual Memory Manager” and “Code Commentary on the
Linux Virtual Memory Manager“.