Provided by: syncthing_1.18.6~ds1-1_amd64 
NAME
syncthing - Syncthing
SYNOPSIS
syncthing [-audit] [-auditfile=<file|-|-->] [-browser-only] [device-id]
[-generate=<dir>] [-gui-address=<address>] [-gui-apikey=<key>]
[-home=<dir> | -config=<dir> -data=<dir>]
[-logfile=<filename>] [-logflags=<flags>]
[-no-browser] [-no-console] [-no-restart] [-paths] [-paused]
[-reset-database] [-reset-deltas] [-unpaused] [-upgrade]
[-upgrade-check] [-upgrade-to=<url>] [-verbose] [-version]
DESCRIPTION
Syncthing lets you synchronize your files bidirectionally 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.
The syncthing core application is a command-line program which usually runs in the
background and handles the synchronization. It provides a built-in, HTML and JavaScript
based user interface to be controlled from a web browser. This frontend communicates with
the core application through some HTTP APIs, which other apps like graphical system
integration helpers can use as well, for greatest flexibility. A link to reach the GUI and
API is printed among the first few log messages.
OPTIONS
-audit Write events to timestamped file audit-YYYYMMDD-HHMMSS.log.
-auditfile=<file|-|-->
Use specified file or stream ("-" for stdout, "--" for stderr) for audit events,
rather than the timestamped default file name.
-browser-only
Open the web UI in a browser for an already running Syncthing instance.
-device-id
Print device ID to command line.
-generate=<dir>
Generate key and config in specified dir, then exit.
-gui-address=<address>
Override GUI listen address. Set this to an address (0.0.0.0:8384) or file path
(/var/run/st.sock, for UNIX sockets).
-home=<dir>
Set common configuration and data directory. The default configuration directory is
$HOME/.config/syncthing (Unix-like), $HOME/Library/Application Support/Syncthing
(Mac) and %LOCALAPPDATA%\Syncthing (Windows).
-config=<dir>
Set configuration directory. Alternative to -home and must be used together with
-data.
-data=<dir>
Set data (e.g. database) directory. Alternative to -home and must be used together
with -config.
-logfile=<filename>
Set destination filename for logging (use "-" for stdout, which is the default
option).
-logflags=<flags>
Select information in log line prefix. 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-console
Hide the console window. (On Windows only)
-no-restart
Do not restart Syncthing when it exits. The monitor process will still run to
handle crashes and writing to logfiles (if configured to).
-paths Print the paths used for configuration, keys, database, GUI overrides, default sync
folder and the log file.
-paused
Start with all devices and folders paused.
-reset-database
Reset the database, forcing a full rescan and resync. Create .stfolder folders in
each sync folder if they do not already exist. Caution: Ensure that all sync
folders which are mountpoints are already mounted. Inconsistent versions may
result if the mountpoint is later mounted and contains older versions.
-reset-deltas
Reset delta index IDs, forcing a full index exchange.
-unpaused
Start with all devices and folders unpaused.
-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
4 Upgrading
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.
PROXIES
Syncthing can use a SOCKS, HTTP, or HTTPS proxy to talk to the outside world. The proxy is
used for outgoing connections only - it is not possible to accept incoming connections
through the proxy. The proxy is configured through the environment variable all_proxy.
Somewhat unusually, this variable must be named in lower case - it is not “ALL_PROXY”. For
example:
$ export all_proxy=socks://192.0.2.42:8081
DEVELOPMENT SETTINGS
The following environment variables modify Syncthing’s behavior in ways that are mostly
useful for developers. Use with care. If you start Syncthing from within service managers
like systemd or supervisor, path expansion may not be supported.
STTRACE
Used to increase the debugging verbosity in specific or all facilities, generally
mapping to a Go package. Enabling any of these also enables microsecond timestamps,
file names plus line numbers. Enter a comma-separated string of facilities to
trace. syncthing -help always outputs an up-to-date list. The valid facility
strings are:
Main and operational facilities:
config Configuration loading and saving.
db The database layer.
main Main package.
model The root hub; the largest chunk of the system. File pulling, index
transmission and requests for chunks.
scanner
File change detection and hashing.
versioner
File versioning.
Networking facilities:
beacon Multicast and broadcast UDP discovery packets: Selected interfaces
and addresses.
connections
Connection handling.
dialer Dialing connections.
discover
Remote device discovery requests, replies and registration of
devices.
nat NAT discovery and port mapping.
pmp NAT-PMP discovery and port mapping.
protocol
The BEP protocol.
relay Relay interaction (strelaysrv).
upnp UPnP discovery and port mapping.
Other facilities:
fs Filesystem access.
events Event generation and logging.
http REST API.
sha256 SHA256 hashing package (this facility currently unused).
stats Persistent device and folder statistics.
sync Mutexes. Used for debugging race conditions and deadlocks.
upgrade
Binary upgrades.
walkfs Filesystem access while walking.
all All of the above.
STBLOCKPROFILE
Write block profiles to block-$pid-$timestamp.pprof every 20 seconds.
STCPUPROFILE
Write a CPU profile to cpu-$pid.pprof on exit.
STDEADLOCKTIMEOUT
Used for debugging internal deadlocks; sets debug sensitivity. Use only under
direction of a developer.
STDEADLOCKTHRESHOLD
Used for debugging internal deadlocks; sets debug sensitivity. Use only under
direction of a developer.
STGUIASSETS
Directory to load GUI assets from. Overrides compiled in assets. Useful for
developing webgui, commonly use STGUIASSETS=gui bin/syncthing.
STHASHING
Specify which hashing package to use. Defaults to automatic based on performance.
Specify “minio” (compatibility) or “standard” for the default Go implementation.
STHEAPPROFILE
Write heap profiles to heap-$pid-$timestamp.pprof each time heap usage increases.
STNODEFAULTFOLDER
Don’t create a default folder when starting for the first time. This variable will
be ignored anytime after the first run.
STNORESTART
Equivalent to the -no-restart flag
STNOUPGRADE
Disable automatic upgrades.
STPROFILER
Set to a listen address such as “127.0.0.1:9090” to start the profiler with HTTP
access, which then can be reached at http://localhost:9090/debug/pprof. See go tool
pprof for more information.
STPERFSTATS
Write running performance statistics to perf-$pid.csv. Not supported on Windows.
STRECHECKDBEVERY
Time before folder statistics (file, dir, … counts) are recalculated from scratch.
The given duration must be parseable by Go’s time.ParseDuration. If missing or not
parseable, the default value of 1 month is used. To force recalculation on every
startup, set it to 1s.
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 (i.e. performance).
SEE ALSO
syncthing-config(5), syncthing-stignore(5), syncthing-device-ids(7),
syncthing-security(7), syncthing-networking(7), syncthing-versioning(7), syncthing-faq(7)
AUTHOR
The Syncthing Authors
COPYRIGHT
2014-2019, The Syncthing Authors