Every time I try to install / upgrade an application or a package, it fails.
In the terminal this message shows up at the end:
(Reading database ... 70%dpkg: unrecoverable fatal error, aborting: reading files list for package 'libgdu0': Input/output error E: Sub-process /usr/bin/dpkg returned an error code (2)
When I try to install something from the software center, the message
The installation or removal of a software package failed appears.