Is there a default for 'pid file' for rsync in daemon mode?

[raf]

On Fri, Jan 01, 2021 at 11:31:11AM +0000, Chris Green via rsync <rsync at lists.samba.org> wrote:

> Francis.Montagnac--- via rsync <rsync at lists.samba.org> wrote:
> > 
> > Hi.
> > 
> > On Fri, 01 Jan 2021 09:57:38 +0000 Chris Green via rsync wrote:
> > 
> > > My backup system crashed a couple of nights ago due to a power cut
> > > (can't really blame it!) and I went and restarted it after the power
> > > came back.  However, as I note above, files in /home/chris/tmp/pid
> > > aren't cleared out so rsync refused to run when systemd attempted to
> > > start it up.
> > 
> > > I guess the pid file should either be in /tmp or somewhere in
> > > /run/user.  However shouldn't there be some sort of sensible default
> > > if it isn't set in rsyncd.conf?
> > 
> > Since rsyncd is launched by systemd, I would say that no pid file is
> > needed: systemd will prevent simultaneous launch of rsyncd.
> > 
> > Can you try without spicifying "pid file" in rsyncd.conf ?
> > 
> > What is the content of the rsyncd.service file on your system ?
> > 
> > On Fedora it is a system (not user) service:
> > 
> > cat /lib/systemd/system/rsyncd.service 
> > [Unit]
> > Description=fast remote file copy program daemon
> > ConditionPathExists=/etc/rsyncd.conf
> > Wants=network-online.target
> > After=network-online.target
> > 
> > [Service]
> > EnvironmentFile=/etc/sysconfig/rsyncd
> > ExecStart=/usr/bin/rsync --daemon --no-detach "$OPTIONS"
> > 
> > [Install]
> > WantedBy=multi-user.target
> > 
> You're quite right, simply removing the 'pid file' setting from
> rsynd.conf seems to work perfectly.
> 
> Maybe this should be noted somwhere in the rsyncd.conf man page.
> 
> -- 
> Chris Green

And maybe the pidfile should be locked so that a new
rsyncd process can tell if it's still in use by a
running rsyncd process. That would fix the problem on
systems that don't have systemd.

cheers,
raf