1SYNCTHING(1) Syncthing SYNCTHING(1)
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6 syncthing - Syncthing
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9 syncthing [-audit] [-auditfile=<file|-|-->] [-browser-only] [device-id]
10 [-generate=<dir>] [-gui-address=<address>] [-gui-apikey=<key>]
11 [-home=<dir> | -config=<dir> -data=<dir>]
12 [-logfile=<filename>] [-logflags=<flags>]
13 [-no-browser] [-no-console] [-no-restart] [-paths] [-paused]
14 [-reset-database] [-reset-deltas] [-unpaused] [-upgrade]
15 [-upgrade-check] [-upgrade-to=<url>] [-verbose] [-version]
16
18 Syncthing lets you synchronize your files bidirectionally across multi‐
19 ple devices. This means the creation, modification or deletion of files
20 on one machine will automatically be replicated to your other devices.
21 We believe your data is your data alone and you deserve to choose where
22 it is stored. Therefore Syncthing does not upload your data to the
23 cloud but exchanges your data across your machines as soon as they are
24 online at the same time.
25
27 -audit Write events to timestamped file audit-YYYYMMDD-HHMMSS.log.
28 -auditfile=<file|-|-->
30 Use specified file or stream ("-" for stdout, "--" for stderr)
31 for audit events, rather than the timestamped default file name.
32 -browser-only
34 Open the web UI in a browser for an already running Syncthing
35 instance.
36 -device-id
38 Print device ID to command line.
39 -generate=<dir>
41 Generate key and config in specified dir, then exit.
42 -gui-address=<address>
44 Override GUI listen address. Set this to an address
45 (0.0.0.0:8384) or file path (/var/run/st.sock, for UNIX sock‐
46 ets).
47 -home=<dir>
49 Set common configuration and data directory. The default config‐
50 uration directory is $HOME/.config/syncthing (Unix-like),
51 $HOME/Library/Application Support/Syncthing (Mac) and %LOCALAPP‐
52 DATA%\Syncthing (Windows).
53 -config=<dir>
55 Set configuration directory. Alternative to -home and must be
56 used together with -data.
57 -data=<dir>
59 Set data (e.g. database) directory. Alternative to -home and
60 must be used together with -config.
61 -logfile=<filename>
63 Set destination filename for logging (use "-" for stdout, which
64 is the default option).
65 -logflags=<flags>
67 Select information in log line prefix. The -logflags value is a
68 sum of the following:
69 • 1: Date
71 • 2: Time
73 • 4: Microsecond time
75 • 8: Long filename
77 • 16: Short filename
79 To prefix each log line with date and time, set -logflags=3 (1 +
81 2 from above). The value 0 is used to disable all of the above.
82 The default is to show time only (2).
83 -no-browser
85 Do not start a browser.
86 -no-console
88 Hide the console window. (On Windows only)
89 -no-restart
91 Do not restart Syncthing when it exits. The monitor process will
92 still run to handle crashes and writing to logfiles (if config‐
93 ured to).
94 -paths Print the paths used for configuration, keys, database, GUI
96 overrides, default sync folder and the log file.
97 -paused
99 Start with all devices and folders paused.
100 -reset-database
102 Reset the database, forcing a full rescan and resync. Create
103 .stfolder folders in each sync folder if they do not already ex‐
104 ist. Caution: Ensure that all sync folders which are mountpoints
105 are already mounted. Inconsistent versions may result if the
106 mountpoint is later mounted and contains older versions.
107 -reset-deltas
109 Reset delta index IDs, forcing a full index exchange.
110 -unpaused
112 Start with all devices and folders unpaused.
113 -upgrade
115 Perform upgrade.
116 -upgrade-check
118 Check for available upgrade.
119 -upgrade-to=<url>
121 Force upgrade directly from specified URL.
122 -verbose
124 Print verbose log output.
125 -version
127 Show version.
128
130 0 Success / Shutdown
131 1 Error
133 2 Upgrade not available
135 3 Restarting
137 4 Upgrading
139 Exit codes over 125 are usually returned by the shell/binary loader/de‐
141 fault signal handler. Exit codes over 128+N on Unix usually represent
142 the signal which caused the process to exit. For example, 128 + 9
143 (SIGKILL) = 137.
144
146 Syncthing can use a SOCKS, HTTP, or HTTPS proxy to talk to the outside
147 world. The proxy is used for outgoing connections only - it is not pos‐
148 sible to accept incoming connections through the proxy. The proxy is
149 configured through the environment variable all_proxy. Somewhat unusu‐
150 ally, this variable must be named in lower case - it is not
151 “ALL_PROXY”. For example:
152 $ export all_proxy=socks://192.0.2.42:8081
154
156 The following environment variables modify Syncthing’s behavior in ways
157 that are mostly useful for developers. Use with care. If you start
158 Syncthing from within service managers like systemd or supervisor, path
159 expansion may not be supported.
160 STTRACE
162 Used to increase the debugging verbosity in specific or all fa‐
163 cilities, generally mapping to a Go package. Enabling any of
164 these also enables microsecond timestamps, file names plus line
165 numbers. Enter a comma-separated string of facilities to trace.
166 syncthing -help always outputs an up-to-date list. The valid fa‐
167 cility strings are:
168 Main and operational facilities:
170 config Configuration loading and saving.
172 db The database layer.
174 main Main package.
176 model The root hub; the largest chunk of the system.
178 File pulling, index transmission and requests for
179 chunks.
180 scanner
182 File change detection and hashing.
183 versioner
185 File versioning.
186 Networking facilities:
188 beacon Multicast and broadcast UDP discovery packets: Se‐
190 lected interfaces and addresses.
191 connections
193 Connection handling.
194 dialer Dialing connections.
196 discover
198 Remote device discovery requests, replies and reg‐
199 istration of devices.
200 nat NAT discovery and port mapping.
202 pmp NAT-PMP discovery and port mapping.
204 protocol
206 The BEP protocol.
207 relay Relay interaction (strelaysrv).
209 upnp UPnP discovery and port mapping.
211 Other facilities:
213 fs Filesystem access.
215 events Event generation and logging.
217 http REST API.
219 sha256 SHA256 hashing package (this facility currently
221 unused).
222 stats Persistent device and folder statistics.
224 sync Mutexes. Used for debugging race conditions and
226 deadlocks.
227 upgrade
229 Binary upgrades.
230 walkfs Filesystem access while walking.
232 all All of the above.
234 STBLOCKPROFILE
236 Write block profiles to block-$pid-$timestamp.pprof every 20
237 seconds.
238 STCPUPROFILE
240 Write a CPU profile to cpu-$pid.pprof on exit.
241 STDEADLOCKTIMEOUT
243 Used for debugging internal deadlocks; sets debug sensitivity.
244 Use only under direction of a developer.
245 STDEADLOCKTHRESHOLD
247 Used for debugging internal deadlocks; sets debug sensitivity.
248 Use only under direction of a developer.
249 STGUIASSETS
251 Directory to load GUI assets from. Overrides compiled in assets.
252 Useful for developing webgui, commonly use STGUIASSETS=gui
253 bin/syncthing.
254 STHASHING
256 Specify which hashing package to use. Defaults to automatic
257 based on performance. Specify “minio” (compatibility) or “stan‐
258 dard” for the default Go implementation.
259 STHEAPPROFILE
261 Write heap profiles to heap-$pid-$timestamp.pprof each time heap
262 usage increases.
263 STNODEFAULTFOLDER
265 Don’t create a default folder when starting for the first time.
266 This variable will be ignored anytime after the first run.
267 STNORESTART
269 Equivalent to the -no-restart flag
270 STNOUPGRADE
272 Disable automatic upgrades.
273 STPROFILER
275 Set to a listen address such as “127.0.0.1:9090” to start the
276 profiler with HTTP access, which then can be reached at
277 http://localhost:9090/debug/pprof. See go tool pprof for more
278 information.
279 STPERFSTATS
281 Write running performance statistics to perf-$pid.csv. Not sup‐
282 ported on Windows.
283 STRECHECKDBEVERY
285 Time before folder statistics (file, dir, … counts) are recalcu‐
286 lated from scratch. The given duration must be parseable by Go’s
287 time.ParseDuration. If missing or not parseable, the default
288 value of 1 month is used. To force recalculation on every
289 startup, set it to 1s.
290 GOMAXPROCS
292 Set the maximum number of CPU cores to use. Defaults to all
293 available CPU cores.
294 GOGC Percentage of heap growth at which to trigger GC. Default is
296 100. Lower numbers keep peak memory usage down, at the price of
297 CPU usage (i.e. performance).
298
300 syncthing-config(5), syncthing-stignore(5), syncthing-device-ids(7),
301 syncthing-security(7), syncthing-networking(7), syncthing-version‐
302 ing(7), syncthing-faq(7)
303
305 The Syncthing Authors
306
308 2014-2019, The Syncthing Authors
309v1 Apr 15, 2021 SYNCTHING(1)