Warn when filesystems are read-only since then login is impossible

[Jens]

Today I was greeted by a text console after logging in to lightdm (Ubuntu standard Unity desktop). No error messages, no nothing (at least on screen).

Since I know my way around Linux I dropped to a console and found that my root fs had been mounted read-only due to an IO error on the harddisk. A novice user would have no idea what to do.

Displaying a warning message saying something like "Your harddisk has been mounted in read-only mode. It might be faulty or there is another system defect which prevented a normal startup procedure. Please reboot, press SHIFT while the computer restarts and choose "Rescue mode" at the boot manager prompt. In the rescue mode menu, try checking for harddisk errors and checking your installed software package database." would help a novice user a lot.

This should be fairly easy to implement. If it is not possible to display notifications before login in lightdm, just change the background image to something which contains this error message in, say, English, German, French, Spanish, and Chinese. This is e.g. what Mac OS X does.

This might apply also to later distributions (I haven't checked).

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: lightdm 1.2.3-0ubuntu2.3
ProcVersionSignature: Ubuntu 3.5.0-37.58~precise1-generic 3.5.7.16
Uname: Linux 3.5.0-37-generic i686
ApportVersion: 2.0.1-0ubuntu17.4
Architecture: i386
Date: Sun Aug 18 10:57:19 2013
InstallationMedia: Ubuntu 12.04.2 LTS "Precise Pangolin" - Release i386 (20130214)
MarkForUpload: True
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
SourcePackage: lightdm
UpgradeStatus: No upgrade log present (probably fresh install)