Fails to launch recovery menu when Postfix & Resolvconf installed
I have two computers affected by this and one that is not, each running Precise. I’ve tracked down the cause, but I’m not sure which of the components involved (friendly-recovery, resolvconf, postfix and upstart) is the culprit, so I’ll file this for friendly-recovery which is at least severly affected. Feel free to correct the target with better insight.
Steps to reproduce:
0. Have the ’postfix’ and ’resolvconf’ packages installed.
1. Boot into recovery mode.
What happens:
The boot proceeds in nonsplash (text) mode, but in the end the recovery menu fails to show up. Instead the graphical greeter is brought up.
What I expect to happen:
For the recovery menu to show up so I can use it.
The cause:
For debugging this, I first enabled logging for friendly-recovery.conf. That log implicated resolvconf, so I enabled logging for resolvconf, and that in turn revealed this:
cp: cannot create regular file `/var/spool/postfix/etc/resolv.conf’: Read-only file system
So I checked, and indeed postfix wasn’t there on my laptop which wasn’t affected. It seems that due to the read-only file system, the resolvconf upstart job fails, which in turn leads to the resolvconf-dependent friendly-recovery job to also fail.
The workaround:
Uninstall postfix if you can afford to.