I have no idea what this means. Was just doing a routine update on my Raspberry Pi:
pi@raspberrypi ~ $ sudo apt-get update E: Archives directory /var/cache/apt/archives/partial is missing. - Acquire (5: Input/output error)
I have no idea what this means.
Currently running Raspbian GNU/Linux 7 (wheezy) Linux raspberrypi 4.1.19-v7+ #858 SMP Tue Mar 15 15:56:00 GMT 2016 armv7l GNU/Linux