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>] [-logfile=<filename>] [-logflags=<flags>]
12 [-no-browser] [-no-console] [-no-restart] [-paths] [-paused]
13 [-reset-database] [-reset-deltas] [-unpaused] [-upgrade]
14 [-upgrade-check] [-upgrade-to=<url>] [-verbose] [-version]
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17 Syncthing lets you synchronize your files bidirectionally across multi‐
18 ple devices. This means the creation, modification or deletion of files
19 on one machine will automatically be replicated to your other devices.
20 We believe your data is your data alone and you deserve to choose where
21 it is stored. Therefore Syncthing does not upload your data to the
22 cloud but exchanges your data across your machines as soon as they are
23 online at the same time.
24
26 -audit Write events to timestamped file audit-YYYYMMDD-HHMMSS.log.
27 -auditfile=<file|-|-->
29 Use specified file or stream ("-" for stdout, "--" for stderr)
30 for audit events, rather than the timestamped default file name.
31 -browser-only
33 Open the web UI in a browser for an already running Syncthing
34 instance.
35 -device-id
37 Print device ID to command line.
38 -generate=<dir>
40 Generate key and config in specified dir, then exit.
41 -gui-address=<address>
43 Override GUI listen address. Set this to an address
44 (0.0.0.0:8384) or file path (/var/run/st.sock, for UNIX sock‐
45 ets).
46 -home=<dir>
48 Set configuration directory. The default configuration directory
49 is $HOME/.config/syncthing (Unix-like), $HOME/Library/Applica‐
50 tion Support/Syncthing (Mac) and %LOCALAPPDATA%\Syncthing (Win‐
51 dows).
52 -logfile=<filename>
54 Set destination filename for logging (use "-" for stdout, which
55 is the default option).
56 -logflags=<flags>
58 Select information in log line prefix. The -logflags value is a
59 sum of the following:
60 · 1: Date
62 · 2: Time
64 · 4: Microsecond time
66 · 8: Long filename
68 · 16: Short filename
70 To prefix each log line with date and time, set -logflags=3 (1 +
72 2 from above). The value 0 is used to disable all of the above.
73 The default is to show time only (2).
74 -no-browser
76 Do not start a browser.
77 -no-console
79 Hide the console window. (On Windows only)
80 -no-restart
82 Disable the Syncthing monitor process which handles restarts for
83 some configuration changes, upgrades, crashes and also log file
84 writing (stdout is still written).
85 -paths Print the paths used for configuration, keys, database, GUI
87 overrides, default sync folder and the log file.
88 -paused
90 Start with all devices and folders paused.
91 -reset-database
93 Reset the database, forcing a full rescan and resync. Create
94 .stfolder folders in each sync folder if they do not already
95 exist. Caution: Ensure that all sync folders which are mount‐
96 points are already mounted. Inconsistent versions may result if
97 the mountpoint is later mounted and contains older versions.
98 -reset-deltas
100 Reset delta index IDs, forcing a full index exchange.
101 -unpaused
103 Start with all devices and folders unpaused.
104 -upgrade
106 Perform upgrade.
107 -upgrade-check
109 Check for available upgrade.
110 -upgrade-to=<url>
112 Force upgrade directly from specified URL.
113 -verbose
115 Print verbose log output.
116 -version
118 Show version.
119
121 0 Success / Shutdown
122 1 Error
124 2 Upgrade not available
126 3 Restarting
128 4 Upgrading
130 Some of these exit codes are only returned when running without a moni‐
132 tor process (with environment variable STNORESTART set). Exit codes
133 over 125 are usually returned by the shell/binary loader/default signal
134 handler. Exit codes over 128+N on Unix usually represent the signal
135 which caused the process to exit. For example, 128 + 9 (SIGKILL) = 137.
136
138 Syncthing can use a SOCKS, HTTP, or HTTPS proxy to talk to the outside
139 world. The proxy is used for outgoing connections only - it is not pos‐
140 sible to accept incoming connections through the proxy. The proxy is
141 configured through the environment variable all_proxy. Somewhat unusu‐
142 ally, this variable must be named in lower case - it is not
143 “ALL_PROXY”. For example:
144 $ export all_proxy=socks://192.0.2.42:8081
146
148 The following environment variables modify Syncthing’s behavior in ways
149 that are mostly useful for developers. Use with care. If you start
150 Syncthing from within service managers like systemd or supervisor, path
151 expansion may not be supported.
152 STTRACE
154 Used to increase the debugging verbosity in specific or all
155 facilities, generally mapping to a Go package. Enabling any of
156 these also enables microsecond timestamps, file names plus line
157 numbers. Enter a comma-separated string of facilities to trace.
158 syncthing -help always outputs an up-to-date list. The valid
159 facility strings are:
160 Main and operational facilities:
162 config Configuration loading and saving.
164 db The database layer.
166 main Main package.
168 model The root hub; the largest chunk of the system.
170 File pulling, index transmission and requests for
171 chunks.
172 scanner
174 File change detection and hashing.
175 versioner
177 File versioning.
178 Networking facilities:
180 beacon Multicast and broadcast UDP discovery packets:
182 Selected interfaces and addresses.
183 connections
185 Connection handling.
186 dialer Dialing connections.
188 discover
190 Remote device discovery requests, replies and reg‐
191 istration of devices.
192 nat NAT discovery and port mapping.
194 pmp NAT-PMP discovery and port mapping.
196 protocol
198 The BEP protocol.
199 relay Relay interaction (strelaysrv).
201 upnp UPnP discovery and port mapping.
203 Other facilities:
205 fs Filesystem access.
207 events Event generation and logging.
209 http REST API.
211 sha256 SHA256 hashing package (this facility currently
213 unused).
214 stats Persistent device and folder statistics.
216 sync Mutexes. Used for debugging race conditions and
218 deadlocks.
219 upgrade
221 Binary upgrades.
222 walkfs Filesystem access while walking.
224 all All of the above.
226 STBLOCKPROFILE
228 Write block profiles to block-$pid-$timestamp.pprof every 20
229 seconds.
230 STCPUPROFILE
232 Write a CPU profile to cpu-$pid.pprof on exit.
233 STDEADLOCKTIMEOUT
235 Used for debugging internal deadlocks; sets debug sensitivity.
236 Use only under direction of a developer.
237 STDEADLOCKTHRESHOLD
239 Used for debugging internal deadlocks; sets debug sensitivity.
240 Use only under direction of a developer.
241 STGUIASSETS
243 Directory to load GUI assets from. Overrides compiled in assets.
244 Useful for developing webgui, commonly use STGUIASSETS=gui
245 bin/syncthing.
246 STHASHING
248 Specify which hashing package to use. Defaults to automatic
249 based on performance. Specify “minio” (compatibility) or “stan‐
250 dard” for the default Go implementation.
251 STHEAPPROFILE
253 Write heap profiles to heap-$pid-$timestamp.pprof each time heap
254 usage increases.
255 STNODEFAULTFOLDER
257 Don’t create a default folder when starting for the first time.
258 This variable will be ignored anytime after the first run.
259 STNORESTART
261 Equivalent to the -no-restart flag. Disable the Syncthing moni‐
262 tor process which handles restarts for some configuration
263 changes, upgrades, crashes and also log file writing (stdout is
264 still written).
265 STNOUPGRADE
267 Disable automatic upgrades.
268 STPROFILER
270 Set to a listen address such as “127.0.0.1:9090” to start the
271 profiler with HTTP access, which then can be reached at
272 http://localhost:9090/debug/pprof. See go tool pprof for more
273 information.
274 STPERFSTATS
276 Write running performance statistics to perf-$pid.csv. Not sup‐
277 ported on Windows.
278 STRECHECKDBEVERY
280 Time before folder statistics (file, dir, … counts) are recalcu‐
281 lated from scratch. The given duration must be parseable by GO’s
282 time.ParseDuration. If missing or not parseable, the default
283 value of 1 month is used. To force recalculation on every
284 startup, set it to 0.
285 GOMAXPROCS
287 Set the maximum number of CPU cores to use. Defaults to all
288 available CPU cores.
289 GOGC Percentage of heap growth at which to trigger GC. Default is
291 100. Lower numbers keep peak memory usage down, at the price of
292 CPU usage (i.e. performance).
293
295 syncthing-config(5), syncthing-stignore(5), syncthing-device-ids(7),
296 syncthing-security(7), syncthing-networking(7), syncthing-version‐
297 ing(7), syncthing-faq(7)
298
300 The Syncthing Authors
301
303 2014-2019, The Syncthing Authors
304v1 Mar 17, 2020 SYNCTHING(1)