Linux filenames are case-sensitive, and hence ext filesystems allow files which are only different by upper vs. lower case. Okay, this is to be expected. More interestingly, it is possible to have a directory Test and a file test within the sampe parent directory. Does not look like we can resolve it gracefully, because under Windows we have to rename one of those. Obviously, it seems better to rename a file. However, this still breaks the program which used a file named test to contain some catalog of the folder named Test .