1UPSMON(8) NUT Manual UPSMON(8)
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6 upsmon - UPS monitor and shutdown controller
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9 upsmon -h
10 upsmon -c command
12 upsmon [-D] [-K] [-p] [-u user]
14
16 upsmon is the client process that is responsible for the most important
17 part of UPS monitoring—shutting down the system when the power goes
18 out. It can call out to other helper programs for notification purposes
19 during power events.
20 upsmon can monitor multiple systems using a single process. Every UPS
22 that is defined in the upsmon.conf(5) configuration file is assigned a
23 power value and a type (slave or master).
24
26 -h
27 Display the help message.
28 -c command
30 Send the command command to the existing upsmon process. Valid
31 commands are:
32 fsd
34 shutdown all master UPSes (use with caution)
35 stop
37 stop monitoring and exit
38 reload
40 reread upsmon.conf(5) configuration file. See "reloading
41 nuances" below if this doesn’t work.
42 -D
44 Raise the debugging level. upsmon will run in the foreground and
45 prints information on stdout about the monitoring process. Use this
46 multiple times for more details.
47 -K
49 Test for the shutdown flag. If it exists and contains the magic
50 string from upsmon, then upsmon will exit with EXIT_SUCCESS. Any
51 other condition will make upsmon exit with EXIT_FAILURE.
52 You can test for a successful exit from upsmon -K in your shutdown
54 scripts to know when to call upsdrvctl(8) to shut down the UPS.
55 -p
57 Run privileged all the time. Normally upsmon will split into two
58 processes. The majority of the code runs as an unprivileged user,
59 and only a tiny stub runs as root. This switch will disable that
60 mode, and run the old "all root all the time" system.
61 This is not the recommended mode, and you should not use this
63 unless you have a very good reason.
64 -u user
66 Set the user for the unprivileged monitoring process. This has no
67 effect when using -p.
68 The default user is set at configure time with configure
70 --with-user=.... Typically this is nobody, but other distributions
71 will probably have a specific nut user for this task. If your
72 notification scripts need to run as a specific user, set it here.
73 You can also set this in the upsmon.conf(5) file with the
75 RUN_AS_USER directive.
76
78 In the upsmon.conf(5), you must specify at least one UPS that will be
79 monitored. Use the MONITOR directive.
80 MONITOR 'system' 'powervalue' 'username' 'password' 'type'
82 The system refers to a upsd(8) server, in the form
84 upsname[@hostname[:port]]. The default hostname is "localhost". Some
85 examples follow:
86 · "su700@mybox" means a UPS called "su700" on a system called
88 "mybox". This is the normal form.
89 · "fenton@bigbox:5678" is a UPS called "fenton" on a system called
91 "bigbox" which runs upsd(8) on port "5678".
92 The powervalue refers to how many power supplies on this system are
94 being driven this UPS. This is typically set to 1, but see the section
95 on power values below.
96 The username is a section in your upsd.users(5) file. Whatever password
98 you set in that section must match the password set in this file.
99 The type set in that section must also match the type here-- master or
101 slave. In general, a master process is one running on the system with
102 the UPS actually plugged into a serial port, and a slave is drawing
103 power from the UPS but can’t talk to it directly. See the section on
104 UPS types for more.
105
107 upsmon senses several events as it monitors each UPS. They are called
108 notify events as they can be used to tell the users and admins about
109 the change in status. See the additional NOTIFY-related sections below
110 for information on customizing the delivery of these messages.
111 ONLINE
113 The UPS is back on line.
114 ONBATT
116 The UPS is on battery.
117 LOWBATT
119 The UPS battery is low (as determined by the driver).
120 FSD
122 The UPS has been commanded into the "forced shutdown" mode.
123 COMMOK
125 Communication with the UPS has been established.
126 COMMBAD
128 Communication with the UPS was just lost.
129 SHUTDOWN
131 The local system is being shut down.
132 REPLBATT
134 The UPS needs to have its battery replaced.
135 NOCOMM
137 The UPS can’t be contacted for monitoring.
138
140 In upsmon.conf(5), you can configure a program called the NOTIFYCMD
141 that will handle events that occur.
142 NOTIFYCMD "path to program"
144 NOTIFYCMD "/usr/local/bin/notifyme"
146 Remember to wrap the path in "quotes" if it contains any spaces.
148 The program you run as your NOTIFYCMD can use the environment variables
150 NOTIFYTYPE and UPSNAME to know what has happened and on which UPS. It
151 also receives the notification message (see below) as the first (and
152 only) argument, so you can deliver a preformatted message too.
153 Note that the NOTIFYCMD will only be called for a given event when you
155 set the EXEC flag by using the notify flags, below:
156
158 By default, all notify events (see above) generate a global message
159 (wall) to all users, plus they are logged via the syslog. You can
160 change this with the NOTIFYFLAG directive in the configuration file:
161 NOTIFYFLAG notifytype flags
163 Examples:
165 · NOTIFYFLAG ONLINE SYSLOG
167 · NOTIFYFLAG ONBATT SYSLOG+WALL
169 · NOTIFYFLAG LOWBATT SYSLOG+WALL+EXEC
171 The flags that can be set on a given notify event are:
173 SYSLOG
175 Write this message to the syslog.
176 WALL
178 Send this message to all users on the system via wall(1).
179 EXEC
181 Execute the NOTIFYCMD.
182 IGNORE
184 Don’t do anything. If you use this, don’t use any of the other
185 flags.
186 You can mix these flags. "SYSLOG+WALL+EXEC" does all three for a given
188 event.
189
191 upsmon comes with default messages for each of the NOTIFY events. These
192 can be changed with the NOTIFYMSG directive.
193 NOTIFYMSG type "message"
195 Examples:
197 · NOTIFYMSG ONLINE "UPS %s is getting line power"
199 · ` NOTIFYMSG ONBATT "Someone pulled the plug on %s"`
201 The first instance of %s is replaced with the identifier of the UPS
203 that generated the event. These messages are used when sending walls to
204 the users directly from upsmon, and are also passed to the NOTIFYCMD.
205
207 The "current overall power value" is the sum of all UPSes that are
208 currently able to supply power to the system hosting upsmon. Any UPS
209 that is either on line or just on battery contributes to this number.
210 If a UPS is critical (on battery and low battery) or has been put into
211 "forced shutdown" mode, it no longer contributes.
212 A "power value" on a MONITOR line in the config file is the number of
214 power supplies that the UPS runs on the current system.
215 MONITOR upsname powervalue username password type
217 Normally, you only have one power supply, so it will be set to 1.
219 MONITOR myups@myhost 1 username mypassword master
221 On a large server with redundant power supplies, the power value for a
223 UPS may be greater than 1. You may also have more than one of them
224 defined.
225 MONITOR ups-alpha@myhost 2 username mypassword master
227 MONITOR ups-beta@myhost 2 username mypassword master
229 You can also set the power value for a UPS to 0 if it does not supply
231 any power to that system. This is generally used when you want to use
232 the upsmon notification features for a UPS even though it’s not
233 actually running the system that hosts upsmon. Don’t set this to
234 "master" unless you really want to power this UPS off when this
235 instance of upsmon needs to shut down for its own reasons.
236 MONITOR faraway@anotherbox 0 username mypassword slave
238 The "minimum power value" is the number of power supplies that must be
240 receiving power in order to keep the computer running.
241 MINSUPPLIES value
243 Typical PCs only have 1, so most users will leave this at the default.
245 MINSUPPLIES 1
247 If you have a server or similar system with redundant power, then this
249 value will usually be set higher. One that requires three power
250 supplies to be running at all times would simply set it to 3.
251 MINSUPPLIES 3
253 When the current overall power value drops below the minimum power
255 value, upsmon starts the shutdown sequence. This design allows you to
256 lose some of your power supplies in a redundant power environment
257 without bringing down the entire system while still working properly
258 for smaller systems.
259
261 upsmon and upsd(8) don’t always run on the same system. When they do,
262 any UPSes that are directly attached to the upsmon host should be
263 monitored in "master" mode. This makes upsmon take charge of that
264 equipment, and it will wait for slaves to disconnect before shutting
265 down the local system. This allows the distant systems (monitoring over
266 the network) to shut down cleanly before upsdrvctl shutdown runs and
267 turns them all off.
268 When upsmon runs as a slave, it is relying on the distant system to
270 tell it about the state of the UPS. When that UPS goes critical (on
271 battery and low battery), it immediately invokes the local shutdown
272 command. This needs to happen quickly. Once it disconnects from the
273 distant upsd(8) server, the master upsmon will start its own shutdown
274 process. Your slaves must all shut down before the master turns off the
275 power or filesystem damage may result.
276 upsmon deals with slaves that get wedged, hang, or otherwise fail to
278 disconnect from upsd(8) in a timely manner with the HOSTSYNC timer.
279 During a shutdown situation, the master upsmon will give up after this
280 interval and it will shut down anyway. This keeps the master from
281 sitting there forever (which would endanger that host) if a slave
282 should break somehow. This defaults to 15 seconds.
283 If your master system is shutting down too quickly, set the FINALDELAY
285 interval to something greater than the default 15 seconds. Don’t set
286 this too high, or your UPS battery may run out of power before the
287 master upsmon process shuts down that system.
288
290 For those rare situations where the shutdown process can’t be completed
291 between the time that low battery is signalled and the UPS actually
292 powers off the load, use the upssched(8) helper program. You can use it
293 along with upsmon to schedule a shutdown based on the "on battery"
294 event. upssched can then come back to upsmon to initiate the shutdown
295 once it has run on battery too long.
296 This can be complicated and messy, so stick to the default critical UPS
298 handling if you can.
299
301 If you have more than one power supply for redundant power, you may
302 also have more than one UPS feeding your computer. upsmon can handle
303 this. Be sure to set the UPS power values appropriately and the
304 MINSUPPLIES value high enough so that it keeps running until it really
305 does need to shut down.
306 For example, the HP NetServer LH4 by default has 3 power supplies
308 installed, with one bay empty. It has two power cords, one per side of
309 the box. This means that one power cord powers two power supply bays,
310 and that you can only have two UPSes supplying power.
311 Connect UPS "alpha" to the cord feeding two power supplies, and UPS
313 "beta" to the cord that feeds the third and the empty slot. Define
314 alpha as a powervalue of 2, and beta as a powervalue of 1. Set the
315 MINSUPPLIES to 2.
316 When alpha goes on battery, your current overall power value will stay
318 at 3, as it’s still supplying power. However, once it goes critical (on
319 battery and low battery), it will stop contributing to the current
320 overall power value. That means the value will be 1 (beta alone), which
321 is less than 2. That is insufficient to run the system, and upsmon will
322 invoke the shutdown sequence.
323 However, if beta goes critical, subtracting its contribution will take
325 the current overall value from 3 to 2. This is just high enough to
326 satisfy the minimum, so the system will continue running as before. If
327 beta returns later, it will be re-added and the current value will go
328 back to 3. This allows you to swap out UPSes, change a power
329 configuration, or whatever, as long as you maintain the minimum power
330 value at all times.
331
333 Besides being able to monitor multiple UPSes, upsmon can also monitor
334 them as different roles. If you have a system with multiple power
335 supplies serviced by separate UPS batteries, it’s possible to be a
336 master on one and a slave on the other. This usually happens when you
337 run out of serial ports and need to do the monitoring through another
338 system nearby.
339 This is also complicated, especially when it comes time to power down a
341 UPS that has gone critical but doesn’t supply the local system. You can
342 do this with some scripting magic in your notify command script, but
343 it’s beyond the scope of this manual.
344
346 When upsmon is forced to bring down the local system, it sets the "FSD"
347 (forced shutdown) flag on any UPSes that it is running in master mode.
348 This is used to synchronize slaves in the event that a master UPS that
349 is otherwise OK needs to be brought down due to some pressing event on
350 the master.
351 You can manually invoke this mode on the master upsmon by starting
353 another copy with -c fsd. This is useful when you want to initiate a
354 shutdown before the critical stage through some external means, such as
355 upssched(8).
356
358 In the event that upsmon can’t reach upsd(8), it declares that UPS
359 "dead" after some interval controlled by DEADTIME in the
360 upsmon.conf(5). If this happens while that UPS was last known to be on
361 battery, it is assumed to have gone critical and no longer contributes
362 to the overall power value.
363 upsmon will alert you to a UPS that can’t be contacted for monitoring
365 with a "NOCOMM" notifier by default every 300 seconds. This can be
366 changed with the NOCOMMWARNTIME setting.
367
369 upsmon usually gives up root powers for the process that does most of
370 the work, including handling signals like SIGHUP to reload the
371 configuration file. This means your upsmon.conf(8) file must be
372 readable by the non-root account that upsmon switches to.
373 If you want reloads to work, upsmon must run as some user that has
375 permissions to read the configuration file. I recommend making a new
376 user just for this purpose, as making the file readable by "nobody"
377 (the default user) would be a bad idea.
378 See the RUN_AS_USER section in upsmon.conf(8) for more on this topic.
380 Additionally, you can’t change the SHUTDOWNCMD or POWERDOWNFLAG
382 definitions with a reload due to the split-process model. If you change
383 those values, you must stop upsmon and start it back up. upsmon will
384 warn you in the syslog if you make changes to either of those values
385 during a reload.
386
388 To test a synchronized shutdown without pulling the plug on your
389 UPS(es), you need only set the forced shutdown (FSD) flag on them. You
390 can do this by calling upsmon again to set the flag, i.e.:
391 upsmon -c fsd
393 After that, the master and the slaves will do their usual shutdown
395 sequence as if the battery had gone critical. This is much easier on
396 your UPS equipment, and it beats crawling under a desk to find the
397 plug.
398
400 upsmon.conf(5)
401
403 Server:
404 upsd(8)
405 Clients:
407 upsc(8), upscmd(8), upsrw(8), upsmon(8)
408 CGI programs:
410 upsset.cgi(8), upsstats.cgi(8), upsimage.cgi(8)
411 Internet resources:
413 The NUT (Network UPS Tools) home page: http://www.networkupstools.org/
414Network UPS Tools 2.7.3. 12/29/2015 UPSMON(8)