configure rsyncd

Just because it took me a long time to find a suitable rsyncd.conf below a copy for safe keeping.

== file starts here, copy the below to /etc/rsyncd.conf

# /etc/rsyncd: configuration file for rsync daemon mode
  # See rsyncd.conf man page for more options.
  # configuration example:

uid = username
#uid = nobody
gid = groupname
#gid = nobody
# use chroot = yes
max connections = 400
read only = false
pid file = /var/run/rsyncd.pid
exclude = lost+found/
transfer logging = yes
log file = /var/log/rsyncd.log
# timeout = 900
# ignore nonreadable = yes
dont compress   = *.gz *.tgz *.zip *.z *.Z *.rpm *.deb *.bz2

[datastore]
       path = /path/to/data/store
       comment = datastore

Also edit /etc/default/rsync and make sure

RSYNC_ENABLE=inetd

is set so you can use systemctl restart rsync or service restart rsync,
whatever fits your flavour of Linux. The above configuration file should be easy to adjust for other OS.