Re: [Nbd] [PATCH] nbd-server: add -D/-dont-daemonize option
- To: Goswin von Brederlow <goswin-v-b@...186...>
- Cc: email@example.com
- Subject: Re: [Nbd] [PATCH] nbd-server: add -D/-dont-daemonize option
- From: "Dmitry V. Levin" <ldv@...1147...>
- Date: Mon, 25 Jun 2012 15:22:06 +0400
- Message-id: <20120625112206.GA1518@...1147...>
- In-reply-to: <87pq8n1zlb.fsf@...860...>
- References: <20120624230358.GA28298@...1147...> <87pq8n1zlb.fsf@...860...>
On Mon, Jun 25, 2012 at 11:59:44AM +0200, Goswin von Brederlow wrote:
> "Dmitry V. Levin" <ldv@...1147...> writes:
> > + <term><option>-D</option></term>
> > + <listitem>
> > + <para>Do not detach and do not become a daemon. This allows
> > + easy monitoring by service managers like systemd.</para>
> > + </listitem>
> > + </varlistentry>
> > + <varlistentry>
> > <term><option>-d</option></term>
> > <listitem>
> > - <para>Do not fork. Useful for debugging.</para>
> > + <para>Do not fork at all. Useful for debugging.</para>
> > </listitem>
> > </varlistentry>
> > <varlistentry>
> I think the difference between -D and -d should be made clearer.
> With -d the server runs in the foreground and accepts a single
> connection only and outputs debug infos, right?
> With -D the server runs in the foreground but forks a child for every
> connect, right?
> Also why should systemd care? It uses cgroups to monitor services. Isn't
> that one of the advantages of systemd over all the other service
The "simple" service type (when the service doesn't daemonize) has an
advantage: systemd can reliably differentiate between main process and
> What I would like to see is socket activation in nbd-server. That way
> the service can be started as needed without performance loss (other
> than the initial startup time once).
That shouldn't be a problem because nbd-server supports inetd mode.