Comment 11 for bug 58430

The best route for practically all users is probably fsck -y. Yes, there's a tiny chance that a) fsck will break something AND b) that something happens to be important to the user AND c) the user could have done better manually BUT d) they didn't bother backing up AND e) they didn't know that the default was fsck -y and change it manually. The confluence of all of these is far less likely than one being missing, and if one is missing then fsck -y is better than plain fsck, or fsck -p. Yes, the consequences of fsck -y failure are more serious than the consequences of fsck -p failure, but the latter shouldn't be neglected and will crop up *much* more commonly, especially as Ubuntu becomes more mainstream.

You could add a scary prompt by default, but this will terrify ordinary users and not be very useful to most power-users either. I think running fsck -y instead of fsck -p by default on Ubuntu Desktop is the best way to fix this issue, with a well-documented way for power-users to alter the setting to the more conventional fsck -p.