The name and format of these files have changed. The Binary Compatibility Package performs the mappings needed to give applications read-only access to these files. Applications requiring write access to these files are not binary compatible. Applications are not expected to write to these files.
Symbolic links to these files are no longer supported. This is, if an application creates a link to /etc/fstab or /etc/mtab, and attempts to open the symbolic link, the open call fails.