Note to myself

/etc/apt/sources.list    holds the archive region

http://unix.stackexchange.com/questions/88644/how-to-check-os-and-version-using-a-linux-command          os information

/dev info
http://linuxboxadmin.com/articles/tools-and-utilities/linux-file-permissions-beyond-rwx.html

char and block file
http://www.linuxnix.com/linuxunix-difference-between-char-and-block-file/