Entering path containing spaces in Terminal
Choose one of the following:


Surround the part of the path containing spaces in quotes:

ln -s /Volumes/"HARDDRV BKUP"/iphonebkup/Backup/ ~/Library/Application\ Support/MobileSync
               ^            ^

Surround the entire path in quotes:

ln -s "/Volumes/HARDDRV BKUP/iphonebkup/Backup/" ~/Library/Application\ Support/MobileSync
      ^                                        ^

Escape the space with a backslash \:

ln -s /Volumes/HARDDRV\ BKUP/iphonebkup/Backup/ ~/Library/Application\ Support/MobileSync
                      ^



Case sensitivity is important in these cases.