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/