Ограничение при использовании ключей
BUGS AND LIMITATIONS The `c', 's', and `u' attributes are not honored by the ext2 and ext3 filesystems as implemented in the current mainline Linux kernels. These attributes may be implemented in future versions of the ext2 and ext3 filesystems. The `j' option is only useful if the filesystem is mounted as ext3. The `D' option is only useful on Linux kernel 2.5.19 and later.