> From: peter boudewijns <ing...@gmail.com> > The entire difference could be pinned down in just 1 directory, 'sbin'.
> I do not know enough about the way Linux writes its files, and how it > determines the size of the files. But it seems to me the git-cloned files > contain empty space that occupies filesystem-space, but is not counted when > calculating the actual filesize ..... OK, the issue is "holes" in files. Unix-like systems have a curious feature: A file is a sequence of bytes, numbered from 0 to (length-1). But an actual disk block for a section of the file is only written when a program writes bytes in that place in the file. If no block is allocated for a certain set of bytes (even though those byte numbers are all less than the file length), those bytes are zero by definition, and if a program tries to read them, it gets zeros. Normally this never comes up because 99% of programs write files starting at the beginning and running to the end. But executable binary files are the exception. They have a complex structure which can leave certain sections of the file existing but filled with zeros by default because the file contents are written out-of-order. This can create a file that occupies less disk space than its length. But ... if you copy such a file with a program that does not notice the long sections of zeros and carefully avoids writing those blocks, the new copy will have actual disk blocks allocated containing those zeros, rather than having them be represented implicitly by the absence of a disk block. Here's one explanation: http://en.wikipedia.org/wiki/Sparse_files#Sparse_files_in_Unix Also, read the "du" and "cp" manual pages, looking for the words "holes" and "sparse", to see situations where this matters. Dale -- You received this message because you are subscribed to the Google Groups "Git for human beings" group. To unsubscribe from this group and stop receiving emails from it, send an email to git-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
