[tor-relays] torrc "permission denied" warning

[Roger Dingledine]

On Mon, Dec 19, 2011 at 08:09:31PM +1100, tony wrote:
> In the Tor logs for a relay, I get the following message:
>
> Dec 19 19:42:23.662 [notice] Renaming old configuration file to  
> "/etc/tor/torrc.orig.1"
> Dec 19 19:42:23.662 [warn] Couldn't rename configuration file  
> "/etc/tor/torrc" to "/etc/tor/torrc.orig.1": Permission denied
>
> I've played around with file permissions but it doesn't help.
>
> Tor seems to be working. Does the error matter?
>
> Running Tor on a Ubuntu Server 10.04 LTS

Sounds like you're using the standard Tor deb and then using Vidalia
(or maybe arm) as the gui. That's fine, but the standard Tor deb doesn't
have write access to its torrc configuration file (everything in /etc
is supposed to be read-only from the perspective of normal programs).

Even with this configuration, you can use Vidalia to change the
configuration of the Tor that is running. Next time you start Tor it
won't remember the changes you made. But when you attach Vidalia to it,
Vidalia will try to make the changes again. I'm not sure if the previous
sentence is entirely accurate anymore.

So if you're happy with how things are going, it's fine.

If you want to change Tor's configuration long-term, you should either
edit your torrc file yourself, or change your Tor so it doesn't start
at boot (e.g. change RUN_DAEMON to "no" in /etc/default/tor), in which
case Vidalia will launch its own Tor, running as your user, and it
will store things in "~/.vidalia/" rather than "/etc/tor/". Downsides
to this approach include a) Tor doesn't start until you start Vidalia,
so if you're being a relay it won't start at boot, and b) running Tor
as a separate user is in principle a wiser thing to do from a security
perspective.

Hope that helps,
--Roger