Arch Linux

The problem is that rsync won't write it out its own pidfile, so we have to. But we can't reliably use pidof(1) like we do with most daemons, since the rsync binary is both the client and the server binary in one.

Example scenario:

You run an rsync to mirror some files on a remote server. While that's going on, you start up your rsync server with "/etc/rc.d/rsync start". Now the rc.d/rsync script grabs the pid of the WRONG rsync binary and stores it in /var/run/rsync.pid. If you run "/etc/rc.d/rsync stop" it will kill the wrong rsync binary.

Anyone know if bash has a special parameter that returns the PID of the last-executed command? I seem to remember it having something like that...

Bash can retrieve the PID of the last executed background process with the $! variable. The problem with that is that rsync will fork and exit, so the PID retrieved from that is not the actual PID of rsync.

We could probably do something like..

pgrep -of "/usr/bin/rsync --daemon" > /var/run/rsyncd.pid

The "-o" should return the oldest started instance pid.
Hopefully that would be the session leader (ppid).

I've also seen issues where /var/run/daemons/rsyncd wasn't deleted on stop and thus wouldn't start again until that file was manually removed. Not sure if it's related or not.

Using pgrep might be the wisest idea here, seeing that we need to look for the "--daemon" arg

I just uploaded rsync 2.6.9-4 in testing. I've used the pgrep suggestion to fix the PID issue and added a 'sleep 1' in the daemon's restart function which seems to fix Dale's problem. Report any success/failures.