Syncthing¶

Synopsis¶

syncthing [-audit] [-generate=<dir>] [-gui-address=<address>]
          [-gui-apikey=<key>] [-gui-authentication=<username:password>]
          [-home=<dir>] [-logflags=<flags>] [-no-browser] [-no-restart]
          [-reset] [-upgrade] [-upgrade-check] [-upgrade-to=<url>]
          [-verbose] [-version]

Description¶

Syncthing is an application that lets you synchronize your files across multiple devices. This means the creation, modification or deletion of files on one machine will automatically be replicated to your other devices. We believe your data is your data alone and you deserve to choose where it is stored. Therefore Syncthing does not upload your data to the cloud but exchanges your data across your machines as soon as they are online at the same time.

Options¶

-audit

Write events to audit file.

-generate=<dir>

Generate key and config in specified dir, then exit.

-gui-address=<address>

Override GUI address.

-gui-apikey=<key>

Override GUI API key.

-gui-authentication=<username:password>

Override GUI authentication; username:password.

-home=<dir>

Set configuration directory. The default configuration directory is: $HOME/.config/syncthing.

-logflags=<flags>

Select information in log line prefix, default 2. The -logflags value is a sum of the following:

1: Date
2: Time
4: Microsecond time
8: Long filename
16: Short filename

To prefix each log line with date and time, set -logflags=3 (1 + 2 from above). The value 0 is used to disable all of the above. The default is to show time only (2).

-no-browser

Do not start a browser.

-no-restart

Do not restart; just exit.

-reset

Reset the database.

-upgrade

Perform upgrade.

-upgrade-check

Check for available upgrade.

-upgrade-to=<url>

Force upgrade directly from specified URL.

-verbose

Print verbose log output.

-version

Show version.

Exit Codes¶

0: Success / Shutdown
1: Error
2: Upgrade not available
3: Restarting
5: Upgrading

Some of these exit codes are only returned when running without a monitor process (with environment variable STNORESTART set). Exit codes over 125 are usually returned by the shell/binary loader/default signal handler. Exit codes over 128+N on Unix usually represent the signal which caused the process to exit. For example, 128 + 9 (SIGKILL) = 137.

Development Settings¶

The following environment variables modify Syncthing’s behavior in ways that are mostly useful for developers. Use with care.

STGUIASSETS

Directory to load GUI assets from. Overrides compiled in assets.

STTRACE

A comma separated string of facilities to trace. The valid facility strings are:

beacon: the beacon package
discover: the discover package
events: the events package
files: the files package
http: the main package; HTTP requests
locks: the sync package; trace long held locks
net: the main package; connections & network messages
model: the model package
scanner: the scanner package
stats: the stats package
upnp: the upnp package
xdr: the xdr package
all: all of the above

STPROFILER

Set to a listen address such as “127.0.0.1:9090” to start the profiler with HTTP access.

STCPUPROFILE

Write a CPU profile to cpu-$pid.pprof on exit.

STHEAPPROFILE

Write heap profiles to heap-$pid-$timestamp.pprof each time heap usage increases.

STBLOCKPROFILE

Write block profiles to block-$pid-$timestamp.pprof every 20 seconds.

STPERFSTATS

Write running performance statistics to perf-$pid.csv. Not supported on Windows.

STNOUPGRADE

Disable automatic upgrades.

GOMAXPROCS

Set the maximum number of CPU cores to use. Defaults to all available CPU cores.

GOGC

Percentage of heap growth at which to trigger GC. Default is 100. Lower numbers keep peak memory usage down, at the price of CPU usage (ie. performance).