Provided by: nut-server_2.8.1-3.1ubuntu2_amd64 
NAME
upsd - UPS information server
SYNOPSIS
upsd -h
upsd [OPTIONS]
DESCRIPTION
upsd is responsible for serving the data from the drivers to the clients. It connects to each driver and
maintains a local cache of the current state. Queries from the clients are served from this cache, so
delays are minimal.
It also conveys administrative messages from the clients back to the drivers, such as starting tests, or
setting values.
Communication between upsd and clients is handled on a TCP port. Configuration details for this port are
described in upsd.conf(8).
This program is essential, and must be running at all times to actually make any use out of the drivers
and clients.
Controls in the configuration files allow you to limit access to the server, but you should also use a
firewall for extra protection. Client processes such as upsmon(8) trust upsd for status information about
the UPS hardware, so keep it secure.
OPTIONS
-c command
Send command to the background process as a signal. Valid commands are:
reload
reread configuration files
stop
stop process and exit
-P pid
Send the command signal above using specified PID number, rather than consulting the PID file. This
can help define service units which start upsd as a foreground process so it does not create a PID
file. See also -FF option as an alternative.
-D
Raise the debugging level. upsd will run in the foreground by default, and will print information on
stdout about the monitoring process. Use this option multiple times for more details.
-F
upsd will run in the foreground, regardless of debugging settings. Specify twice (-FF or -F -F) to
save the PID file even in this mode.
-B
upsd will run in the background, regardless of debugging settings.
-h
Display the help text.
-r directory
upsd will chroot(2) to directory shortly after startup and before parsing any configuration files
with this option set. You can use this to create a "jail" for greater security.
You must coordinate this with your drivers, as upsd must be able to find the state path within
directory. See upsdrvctl(8) and nutupsdrv(8).
-u user
Switch to user user after startup if started as root. This overrides whatever you may have compiled
in with configure --with-user.
-V
Display the version of the program.
RELOADING
upsd can reload its configuration files without shutting down the process if you send it a SIGHUP or
start it again with -c reload. This only works if the background process is able to read those files, and
if the daemon did save a PID file when it started.
Note
Service instances wrapped by systemd or SMF might not save them by default — use respective
reload/refresh framework actions instead then), e.g. systemctl reload nut-server
NUT releases after 2.8.0 define aliases for these units, so if your Linux distribution uses
NUT-provided unit definitions, systemctl reload upsd may also work.
If you think that upsd can’t reload, check your syslog for error messages. If it’s complaining about not
being able to read the files, then you need to adjust your system to make it possible. Either change the
permissions on the files, or run upsd as another user that will be able to read them.
DO NOT make your upsd.conf or upsd.users world-readable, as those files hold important authentication
information. In the wrong hands, it could be used by some evil person to spoof your primary-mode upsmon
and command your systems to shut down.
DIAGNOSTICS
upsd expects the drivers to either update their status regularly or at least answer periodic queries,
called pings. If a driver doesn’t answer, upsd will declare it "stale" and no more information will be
provided to the clients.
If upsd complains about staleness when you start it, then either your driver or configuration files are
probably broken. Be sure that the driver is actually running, and that the UPS definition in ups.conf(5)
is correct. Also make sure that you start your driver(s) before starting upsd.
Data can also be marked stale if the driver can no longer communicate with the UPS. In this case, the
driver should also provide diagnostic information in the syslog. If this happens, check the serial or USB
cabling, or inspect the network path in the case of a SNMP UPS.
ACCESS CONTROL
If the server is build with tcp-wrappers support enabled, it will check if the NUT username is allowed to
connect from the client address through the /etc/hosts.allow and /etc/hosts.deny files. Note that this
will only be done for commands that require to be logged into the server. Further details are described
in hosts_access(5).
FILES
The general upsd configuration file is upsd.conf(5). The administrative functions like SET and INSTCMD for users are defined and controlled in upsd.users(5). UPS definitions are found in ups.conf(5).
ENVIRONMENT VARIABLES
NUT_DEBUG_LEVEL sets default debug verbosity if no -D arguments were provided on command line, but does
not request that the daemon runs in foreground mode.
NUT_CONFPATH is the path name of the directory that contains upsd.conf and other configuration files. If
this variable is not set, upsd uses a built-in default, which is often /usr/local/ups/etc.
NUT_STATEPATH is the path name of the directory in which upsd keeps state information. If this variable
is not set, upsd uses a built-in default, which is often /var/state/ups. The STATEPATH directive in
upsd.conf(5) overrides this variable.
NUT_ALTPIDPATH is the path name of the directory in which upsd and drivers store .pid files. If this
variable is not set, upsd and drivers use either NUT_STATEPATH if set, or ALTPIDPATH if set, or otherwise
the built-in default STATEPATH.
SEE ALSO
Clients:
• upsc(8)
• upscmd(8)
• upsrw(8)
• upslog(8)
• upsmon(8)
CGI programs:
• upsset.cgi(8)
• upsstats.cgi(8)
• upsimage.cgi(8)
Driver control:
• nut-driver-enumerator(8)
• upsdrvctl(8)
• upsdrvsvcctl(8)
Drivers:
• nutupsdrv(8)
• adelsystem_cbi(8)
• al175(8)
• apc_modbus(8)
• apcsmart-old(8)
• apcsmart(8)
• apcupsd-ups(8)
• asem(8)
• bcmxcp(8)
• bcmxcp_usb(8)
• belkin(8)
• belkinunv(8)
• bestfcom(8)
• bestfortress(8)
• bestuferrups(8)
• bestups(8)
• blazer-common(8)
• blazer_ser(8)
• blazer_usb(8)
• clone(8)
• dummy-ups(8)
• etapro(8)
• everups(8)
• gamatronic(8)
• generic_gpio(8)
• generic_modbus(8)
• genericups(8)
• huawei-ups2000(8)
• isbmex(8)
• ivtscd(8)
• liebert-esp2(8)
• liebert(8)
• macosx-ups(8)
• masterguard(8)
• metasys(8)
• mge-shut(8)
• mge-utalk(8)
• microdowell(8)
• microsol-apc(8)
• netxml-ups(8)
• nut-ipmipsu(8)
• nut_usb_addvars(8)
• nutdrv_atcl_usb(8)
• nutdrv_qx(8)
• nutdrv_siemens_sitop(8)
• oneac(8)
• optiups(8)
• phoenixcontact_modbus(8)
• pijuice(8)
• powercom(8)
• powerman-pdu(8)
• powerpanel(8)
• rhino(8)
• richcomm_usb(8)
• riello_ser(8)
• riello_usb(8)
• safenet(8)
• sms_ser(8)
• snmp-ups(8)
• socomec_jbus(8)
• solis(8)
• tripplite(8)
• tripplite_usb(8)
• tripplitesu(8)
• upscode2(8)
• usbhid-ups(8)
• victronups(8)
Internet resources:
The NUT (Network UPS Tools) home page: https://www.networkupstools.org/