Raspberry Pi: BitTorrent sync alternative Syncthing

Btsync is a great tool for syncing data and backups to several different locations. By leveraging the torrent technology you can increase the download/upload speeds by adding more nodes to the swarm. Installing Btsync on a built in system like the Raspberry Pi or Odroid-C1 is a challenge since it consumes a lot of system resources, read more about installing BitTorrent Sync on Raspberry Pi. Reading up on the subject a lot of people did suggest that Syncthing takes up less system resources then btsync so let’s install it and try it out.

Pre requirements

Same as for the btsync install I need to access my NAS root NFS share to get all the data that I will sync. So first I setup a mount point and do a persistent mount of that share.

[bash]sudo mkdir /mnt/stroot
sudo chmod 777 /mnt/stroot[/bash]

Then let’s edit /etc/fstab so run sudo nano /etc/fstab and add a line representing your share.

[bash]192.168.0.5:/nfs /mnt/stroot nfs rsize=8192,wsize=8192,timeo=14,nolock,intr 0 0[/bash]

This will give me the root for all the shares so I don’t have to map every share individually but are able to access all of them as subfolders.

To test this out we can run sudo mount -a. Then reboot the system and check that the mount is persistent. If you have issues with the persistence and are running DHCP please see my Raspbian:fstab doesn’t mount NFS on boot article for reference.

Install

Download the Syncthing repository key and add it.

[bash]wget -O – https://syncthing.net/release-key.txt | sudo apt-key add -[/bash]

Add the repository

[bash]echo "deb http://apt.syncthing.net/ syncthing release" | sudo tee /etc/apt/sources.list.d/syncthing.list[/bash]

Update the repository with sudo apt-get update and then install with

[bash]sudo apt-get install syncthing[/bash]

Then try to run it with syncthing, as soon as you see it start properly you can stop it with CTRL + C. To set it up to run as a service we need first reconfigure the bind address.

[bash]nano /home/pi/.config/syncthing/config.xml[/bash]

Look for the gui option, it should look like this:

[xml]<gui enabled="true" tls="false">
<address>127.0.0.1:8384</address>
<apikey>2Yy41r5k5oocz6rDIWVsKeP4wUx9uknD</apikey>
<theme>dark</theme>
</gui>[/xml]

Here you can change all the settings in regard to the UI. Change the bind address to 0.0.0.0 so it will respond to all ip addresses. If your running on a fixed IP and not DHCP you can go ahead and bind it to a specific address if you like. You can also change the tls setting to true, enabling https for the UI. This will however result in a security warning when you browse to the UI due to the self signed certificate.

If you now run syncthing from the command line it will bind to the IP and you will be able to navigate to the UI.

Autostart Syncthing as a “service”

First we need to create a init.d script for Syncthing.

[bash]sudo nano /etc/init.d/syncthing[/bash]

Copy and paste the following into it:

[bash]#!/bin/sh
### BEGIN INIT INFO
# Provides: Syncthing
# Required-Start: $local_fs $remote_fs $network
# Required-Stop: $local_fs $remote_fs $network
# Default-Start: 2 3 4 5
# Default-Stop: 0 1 6
# Short-Description: Syncthing
# Description: Syncthing is for backups
### END INIT INFO

# Documentation available at
# http://refspecs.linuxfoundation.org/LSB_3.1.0/LSB-Core-generic/LSB-Core-generic/iniscrptfunc.html
# Debian provides some extra functions though
. /lib/lsb/init-functions

DAEMON_NAME="syncthing"
DAEMON_USER=pi
DAEMON_PATH="/usr/bin/syncthing"
DAEMON_OPTS=""
DAEMON_PWD="${PWD}"
DAEMON_DESC=$(get_lsb_header_val $0 "Short-Description")
DAEMON_PID="/var/run/${DAEMON_NAME}.pid"
DAEMON_NICE=0
DAEMON_LOG=’/var/log/syncthing’

[ -r "/etc/default/${DAEMON_NAME}" ] &amp;&amp; . "/etc/default/${DAEMON_NAME}"

do_start() {
local result

pidofproc -p "${DAEMON_PID}" "${DAEMON_PATH}" &gt; /dev/null
if [ $? -eq 0 ]; then
log_warning_msg "${DAEMON_NAME} is already started"
result=0
else
log_daemon_msg "Starting ${DAEMON_DESC}" "${DAEMON_NAME}"
touch "${DAEMON_LOG}"
chown $DAEMON_USER "${DAEMON_LOG}"
chmod u+rw "${DAEMON_LOG}"
if [ -z "${DAEMON_USER}" ]; then
start-stop-daemon –start –quiet –oknodo –background
–nicelevel $DAEMON_NICE
–chdir "${DAEMON_PWD}"
–pidfile "${DAEMON_PID}" –make-pidfile
–exec "${DAEMON_PATH}" — $DAEMON_OPTS
result=$?
else
start-stop-daemon –start –quiet –oknodo –background
–nicelevel $DAEMON_NICE
–chdir "${DAEMON_PWD}"
–pidfile "${DAEMON_PID}" –make-pidfile
–chuid "${DAEMON_USER}"
–exec "${DAEMON_PATH}" — $DAEMON_OPTS
result=$?
fi
log_end_msg $result
fi
return $result
}

do_stop() {
local result

pidofproc -p "${DAEMON_PID}" "${DAEMON_PATH}" &gt; /dev/null
if [ $? -ne 0 ]; then
log_warning_msg "${DAEMON_NAME} is not started"
result=0
else
log_daemon_msg "Stopping ${DAEMON_DESC}" "${DAEMON_NAME}"
killproc -p "${DAEMON_PID}" "${DAEMON_PATH}"
result=$?
log_end_msg $result
rm "${DAEMON_PID}"
fi
return $result
}

do_restart() {
local result
do_stop
result=$?
if [ $result = 0 ]; then
do_start
result=$?
fi
return $result
}

do_status() {
local result
status_of_proc -p "${DAEMON_PID}" "${DAEMON_PATH}" "${DAEMON_NAME}"
result=$?
return $result
}

do_usage() {
echo $"Usage: $0 {start | stop | restart | status}"
exit 1
}

case "$1" in
start) do_start; exit $? ;;
stop) do_stop; exit $? ;;
restart) do_restart; exit $? ;;
status) do_status; exit $? ;;
*) do_usage; exit 1 ;;
esac[/bash]

Make the init.d script executable and make it start on boot.

[bash]sudo chmod +x /etc/init.d/syncthing
sudo update-rc.d syncthing defaults[/bash]

Now you can start the Syncthing service like any other service.

[bash]sudo service syncthing start[/bash]

Conclusion

The reason I looked into Syncthing in the first place was the memory consumption of btsync. After running a few tests I can see that it’s the same with Syncthing. By the time I’m writing this my btsync instance running on my Odroid-C1 has index almost 4Tb of data and is running smoothly. Syncthing is opensource, which I like a lot, but it’s a much more immature product then btsync. The windows client is just an .exe that will run a local web server that you connect to. Btsync seems more mature and robust from my initial tests. Syncthing will probably develop into something better but at this time I will go with btsync instead. Btsync is also developed by the torrent technology creators which make me believe in it even more. Install guide for btsync…

Why don’t you install both of them and try them out and let me know what you think in the comments?