Comment 12 for bug 324233

I believe I have found the cause of this bug within nm-named-manager.c.

Should Network Manager fail to update the resolver via the resolvconf script, then it will fall through to the default behaviour (ie write details to a temp file and then overwrites /etc/resolv.conf). The code treats /sbin/resolvconf not being installed in the same way as it would treat execution of resolvconf failing, which is why we have this problem of NetworkManager sometimes overwriting the configuration.

I can think of two solutions to this problem.

1. If we find /etc/resolv.conf is a SYMLINK, follow it and update the target file.
2. Ignore resolvconf failures, if /etc/resolv.conf is a SYMLINK

I think option 1 is preferable, as it is least likely to leave you without a functioning resolver.
I have patches for both methods, and I will upload them shortly.

Cheers,
Mark