SYNCTHING(1)

NAME
syncthing - Syncthing

SYNOPSIS

syncthing [-audit] [-auditfile=<file|-|-->] [-browser-only] [device-id]
          [-generate=<dir>] [-gui-address=<address>] [-gui-apikey=<key>]
          [-home=<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 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 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.

-home=<dir>
    Set configuration directory. The default configuration directory is $HOME/.config/syncthing (Unix-like), $HOME/Library/Application Support/Syncthing (Mac) and %LOCALAPPDATA%\Syncthing (Windows).

-logfile=<filename>
    Set destination filename for logging (use "-" for stdout, which is the default option).

-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-console
    Hide the console window. (On Windows only)

-no-restart
    Disable the Syncthing monitor process which handles restarts for some configuration changes, upgrades, crashes and also log file writing (stdout is still written).

-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.

DEPRECATED OPTIONS

-gui-apikey=<key>
    Override GUI API key (deprecated as of v0.13, to be removed in the future - do not use).

EXIT CODES

0   Success / Shutdown

1   Error

2   Upgrade not available

3   Restarting

4   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. If you start Syncthing from within service managers like systemd or supervisor, path expansion may not be supported.

STNODEFAULTFOLDER
    Don't create a default folder when starting for the first time. This variable will be ignored anytime after the first run.

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

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:

main
    Main package.

model
    The root hub; the largest chunk of the system. File pulling, index transmission and requests for chunks.

config
    Configuration loading and saving.

db  The database layer.

scanner
    File change detection and hashing.

versioner
    File versioning.

Networking facilities:

beacon
    Multicast and broadcast discovery packets.

connections
    Connection handling.

dialer
    Dialing connections.

discover
    Remote device discovery requests, replies and registration of devices.

relay
    Relay interaction.

protocol
    The BEP protocol.

nat NAT discovery and port mapping.

pmp NAT-PMP discovery and port mapping.

upnp
    UPnP discovery and port mapping.

Other facilities:

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.

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.

STDEADLOCK
    Used for debugging internal deadlocks. Use only under direction of a developer.

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.

STNORESTART
    Equivalent to the -no-restart argument. Disable the Syncthing monitor process which handles restarts for some configuration changes, upgrades, crashes and also log file writing (stdout is still written).

STNOUPGRADE
    Disable automatic upgrades.

STHASHING
    Specify which hashing package to use. Defaults to automatic based on performance. Specify "minio" (compatibility) or "standard" for the default Go implementation.

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
2015, The Syncthing Authors