File system check

To force fsck during next system start just run: sudo touch /forcefsck.

Note that using fastboot option in grub startup options disables fsck entirely.

Turn off Nepomuk and Akonadi in KDE4

If you don't need Nepomuk Semantic Desktop you can turn it off in System Settings > Desktop Search. After that you have to disable akonadi server to get rid of the error notification about problems with connecting to nepomuk.
This you can disable in:
~/.config/akonadi/akonadiserverrc
where you should change StartServer=true to StartServer=false.
Note that this change will disable KDEs KIM services such as KMail.