# UPS.CONF(5)

## NAME

ups.conf - UPS definitions for Network UPS Tools

## DESCRIPTION

This file is read by the driver controller upsdrvctl(8), the UPS drivers which use the common core (see nutupsdrv(8)), nut-driver-enumerator(8), and the NUT data server upsd(8). The file begins with global directives, and then each UPS has a section which contains a number of directives that set parameters for that UPS.

A UPS section begins with the name of the UPS in brackets, and continues until the next UPS name in brackets or until EOF. The name "default" is used internally in upsd(8), so you can’t use it in this file.

You must define the driver and port elements for each entry. Anything after that in a section is optional. A simple example might look like this:

    [myups]
            driver = blazer_ser
            port = /dev/ttyS0
            desc = "Web server UPS"

A slightly more complicated version includes some extras for the hardware-specific part of the driver:

    [bigups]
            driver = apcsmart
            port = /dev/cua00
            cable = 940-0095B
            sdtype = 2
            desc = "Database server UPS"

In this case, the apcsmart(8) driver will receive variables called "cable" and "sdtype" which have special meanings. See the man pages of your driver(s) to learn which variables are supported and what they do.

Here is another example, when connecting a serial UPS on Windows:

    [windows-ups]
            driver = mge-shut
            port = "\\\\.\\COM10"
            desc = "UPS on a Windows machine"

## IMPORTANT NOTES

- Contents of this file should be pure ASCII (character codes not in range would be ignored with a warning message).

- Balance the run-time user permissions to access the file (and perhaps the directory it is in) for only `upsd` and the drivers to be able to read it; write access is not needed. It is common to use `chown root:nut` and `chmod 640` to set up acceptable file permissions.

  - Packages (and build recipes) typically prepare one set of user and group accounts for NUT. Custom builds with minimal configuration might even use `nobody:nogroup` or similar, which is inherently insecure.

  - On systems with extra security concerns, NUT drivers, data server should run as separate user accounts which would be members of one same group for shared access to local Unix socket files and the directory they are in, as well for reading `ups.conf`, but different groups for other configuration file access. This would need some daemons to use customized `user`, `group`, `RUN_AS_USER` and/or `RUN_AS_GROUP` settings to override the single built-in value.

  - Note that the monitoring, logging, etc. clients are networked-only. They do not need access to these files and directories, and can run as an independent user and group altogether.

  - Keep in mind the security of also any backup copies of this file, e.g. the archive files it might end up in.

## GLOBAL DIRECTIVES

chroot

  Optional. The driver will chroot(2) to this directory during initialization. This can be useful when securing systems.

driverpath

  Optional. Path name of the directory in which the UPS driver executables reside. If you don’t specify this, the programs look in a built-in default directory, which is often /usr/local/ups/bin.

statepath

  Optional. Path name of the directory in which the UPS drivers should place their state sockets for local communication with `upsd` data server, rather than the default location that was compiled into the program, which is often /var/state/ups.

  Note that the drivers must use the same path as `upsd`, so the data server would prefer this setting from `ups.conf` global section, if present, over its own in `upsd.conf`.

  Environment variable `NUT_STATEPATH` set by caller can override this setting.

maxstartdelay

  Optional. Same as the UPS field of the same name, but this is the default for UPSes that don’t have the field.

maxretry

  Optional. Specify the number of attempts to start the driver(s), in case of failure, before giving up. A delay of retrydelay is inserted between each attempt. Caution should be taken when using this option, since it can impact the time taken by your system to start.

  The default is 1 attempt.

nowait

  Optional. Specify to upsdrvctl to not wait at all for the driver(s) to execute the request command.

  The default (omission) is to wait.

  It can be overridden by `NUT_IGNORE_NOWAIT` environment variable (e.g. used to work around certain issues with systemd otherwise).

retrydelay

  Optional. Specify the delay between each restart attempt of the driver(s), as specified by maxretry. Caution should be taken when using this option, since it can impact the time taken by your system to start.

  The default is 5 seconds.

pollinterval

  Optional. The status of the UPS will be refreshed after a maximum delay which is controlled by this setting. This is normally 2 seconds. This setting may be useful if the driver is creating too much of a load on your monitoring system or network.

  Note that some drivers (such as usbhid-ups(8), snmp-ups(8) and nutdrv_qx(8)) also have an option called pollfreq which controls how frequently some of the less critical parameters are polled. Details are provided in the respective driver man pages.

synchronous

  Optional. The drivers work by default in asynchronous mode initially but can fall back to synchronous mode if writes to server socket failed (i.e synchronous=auto). This means that all data are pushed by the driver on the communication socket to upsd (Unix socket on Unix, Named pipe on Windows) without waiting for these data to be actually consumed. With some HW, such as ePDUs, that can produce a lot of data, asynchronous mode may cause some congestion, resulting in the socket to be full, and the driver to appear as not connected. In such case, the driver will provide the following debug message:

      write XX bytes to socket Y failed

  By enabling the synchronous flag (value = yes), the driver will wait for data to be consumed by upsd, prior to publishing more. This can be enabled either globally or per driver.

  The default of auto acts like no (i.e. asynchronous mode) for backward compatibility of the driver behavior, until communications fail with a "Resource temporarily unavailable" condition, which happens when the driver has many data points to send in a burst, and the server can not handle that quickly enough so the buffer fills up.

user

  Optional. Overrides the compiled-in default unprivileged username for all NUT device drivers. See the discussion of the `-u` option in nutupsdrv(8) for details.

group

  Optional. Overrides the compiled-in (and/or global-section) default unprivileged group name for all NUT device drivers, used for the socket file access. See the discussion of the `-g` option in nutupsdrv(8) for details. This may be specifically useful for ensuring access to dynamic device filesystem nodes, such as USB (or serial-over-USB) hot-plug support, or with device filesystems re-generated by an OS for every reboot.

debug_min INTEGER

  Optional. Specify a minimum debug level for all driver daemons and for the upsdrvctl(8) tool, e.g. for troubleshooting a deployment without changing init scripts, without impacting foreground or background running mode directly. Command-line option `-D` can only increase this verbosity level.

LIBUSB_DEBUG INTEGER

  Optional. For run-time troubleshooting of USB-capable NUT drivers, you can specify verbosity of LibUSB specific debugging as a numeric value such as `4` ("All messages are emitted"). Should not have any practical impact on other NUT drivers.

  For more details, including the currently supported values for your version of the library, see e.g.:

  - https://libusb.sourceforge.io/api-1.0/

  - https://libusb.sourceforge.io/api-1.0/group__libusb__lib.html

## UPS FIELDS

driver

  Required. This specifies which program will be monitoring this UPS. You need to specify the one that is compatible with your hardware. See nutupsdrv(8) for more information on drivers in general and pointers to the man pages of specific drivers.

port

  Required. This is the serial port where the UPS is connected. On a Linux system, the first serial port usually is /dev/ttyS0. On FreeBSD and similar systems, it probably will be /dev/cuaa0. On Windows, the first serial port will be "\\\\.\\COM1" (note the escaped slashes).

user

  Optional. Overrides the compiled-in (and/or global-section) default unprivileged username for a particular NUT device driver. See the discussion of the `-u` option in nutupsdrv(8) for details. This may be specifically useful for ensuring access to dynamic device filesystem nodes, such as USB (or serial-over-USB) hot-plug support, or with device filesystems re-generated by an OS for every reboot.

group

  Optional. Overrides the compiled-in (and/or global-section) default unprivileged group name for a particular NUT device driver, used for the socket file access. See the discussion of the `-g` option in nutupsdrv(8) for details. This may be specifically useful for ensuring access to dynamic device filesystem nodes, such as USB (or serial-over-USB) hot-plug support, or with device filesystems re-generated by an OS for every reboot.

sdorder

  Optional. When you have multiple UPSes on your system, you usually need to turn them off in a certain order. upsdrvctl shuts down all the 0s, then the 1s, 2s, and so on. To exclude a UPS from the shutdown sequence, set this to -1.

  The default value for this parameter is 0.

sdcommands

  Optional. Comma-separated list of instant command name(s) to send to the UPS when you request its shutdown.

  Default logic is built into each driver (where supported) and can be referenced here as the `shutdown.default` value.

  The primary use-case is for devices whose drivers "natively" support trying several commands, but the built-in order of those calls a command that is mis-handled by the specific device model (so the handling is reported as successful and the loop stops, but nothing happens as far as the load power-down is concerned).

  Another use-case is differentiation of automated power-off scenarios where the UPS and its load should stay "OFF" (e.g. by building emergency power-off) vs. those where the load should return to work automatically when it is safe to do so. NOTE: This would currently need editing of `ups.conf` for such cases before `nutshutdown` sees the file; but could be better automated in future NUT releases.

  Note | User-provided commands may be something other than actual shutdown, e.g. a beeper to test that the INSTCMD happened such and when expected, and the device was contacted, without impacting the load fed by the UPS.

allow_killpower

  Optional. This allows you to request `driver.killpower` instant command, to immediately call the driver-specific default implementation of `upsdrv_shutdown()` method, for same effect as when a NUT driver is started with `-k` command-line flag. This option can be toggled with upsrw(8) as `driver.flag.allow_killpower` during run-time.

desc

  Optional. This allows you to set a brief description that upsd will provide to clients that ask for a list of connected equipment.

nolock

  Optional. When you specify this, the driver skips the port locking routines every time it starts. This may allow other processes to seize the port if you start more than one accidentally.

  You should only use this if your system won’t work without it.

  This may be needed on Mac OS X systems.

ignorelb

  Optional. When you specify this, the driver ignores a low battery condition flag that is reported by the UPS (some devices will switch off almost immediately after setting this flag, or will report this as soon as the mains fails). Instead it will use either of the following conditions to determine when the battery is low:

      battery.charge < battery.charge.low
      battery.runtime < battery.runtime.low

  The idea is to set the battery.charge.low and/or battery.runtime.low levels in ups.conf to a value that gives enough time to cleanly shutdown your system:

      override.battery.charge.low = 30
      override.battery.runtime.low = 180

  In order for this to work, your UPS should be able to (reliably) report charge and/or runtime remaining on battery. Use with caution!

maxstartdelay

  Optional. This can be set as a global variable above your first UPS definition and it can also be set in a UPS section. This value controls how long upsdrvctl will wait for the driver to finish starting. This keeps your system from getting stuck due to a broken driver or UPS.

  Note that after this time `upsdrvctl` would just move along with its business (whether retrying the same driver if `maxretry>1`, or trying another driver if starting them all, or just eventually exit); however, each such most recently started "stuck" driver process may be further initializing in the background, and might even succeed eventually.

  They would not be actively killed by `upsdrvctl` after this timeout expires.

  The default is 75 seconds.

maxretry

  Optional. This can be set as a global variable above your first UPS definition and it can also be set in a UPS section. See explanation above, in the global section.

retrydelay

  Optional. This can be set as a global variable above your first UPS definition and it can also be set in a UPS section. See explanation above, in the global section.

synchronous

  Optional. Same as the global directive of the same name, but this is for a specific device.

usb_set_altinterface[=altinterface]

  Optional. Force the USB code to call `usb_set_altinterface(0)`, as was done in NUT 2.7.2 and earlier. This should not be necessary, since the default for `bAlternateSetting` (as shown in lsusb) is zero on all USB devices seen to date. However, this redundant call to `usb_set_altinterface()` prevents certain UPSes from working on Mac OS X. If your UPS requires explicitly setting the alternate interface, include this flag, and email the nut-upsdev list with details about your UPS and operating system.

usb_config_index
usb_hid_rep_index
usb_hid_desc_index
usb_hid_ep_in
usb_hid_ep_out

  Optional. Force use of specific interface, endpoint, descriptor index etc. numbers, rather than defaulting to 0 (rarely other values in certain drivers for some devices known to use non-zero numbers). Specified as a hexadecimal number.

  As a rule of thumb for `usb_hid_desc_index` discovery, you can see larger `wDescriptorLength` values (roughly 600+ bytes) in reports of `lsusb` or similar tools.

default.<variable>

  Optional. Set a default value for <variable> which is used in case the UPS doesn’t provide a value, but will be overwritten if a value is available from the UPS:

      default.input.voltage.nominal = 230

  The above will report the nominal input voltage to be 230, unless the UPS tells us differently.

override.<variable>

  Optional. Set a value for <value> that overrides any value that may be read from the UPS. Used for overriding values from the UPS that are clearly wrong (some devices report wrong values for battery voltage for instance):

      override.battery.voltage.nominal = 12

  Use with caution! This will only change the appearance of the variable to the outside world, internally in the UPS the original value is used.

All other fields are passed through to the hardware-specific part of the driver. See those manuals for the list of what is allowed.

debug_min INTEGER

  Optional. Specify a minimum debug level for this driver daemon, e.g. for troubleshooting a deployment, without impacting foreground or background running mode directly. If the global `debug_min` is also set, this driver-level setting overrides it. Command-line option `-D` can only increase this verbosity level.

LIBUSB_DEBUG INTEGER

  Optional. For run-time troubleshooting of USB-capable NUT drivers, you can specify verbosity of LibUSB specific debugging as a numeric value such as `4` ("All messages are emitted").

  For more details, including the currently supported values for your version of the library, see e.g.:

  - https://libusb.sourceforge.io/api-1.0/

  - https://libusb.sourceforge.io/api-1.0/group__libusb__lib.html

## INTEGRATION

upsdrvctl(8) uses this file to start and stop the drivers.

The drivers themselves also obtain configuration data from this file. Each driver looks up its section and uses that to configure itself.

upsd(8) learns about which UPSes are installed on this system by reading this file. If this system is called "doghouse" and you have defined a UPS in your ups.conf called "snoopy", then you can monitor it from upsc(8) or similar as "snoopy@doghouse".

## SEE ALSO

upsd(8), nutupsdrv(8), upsdrvctl(8), upsdrvsvcctl(8)

### Internet resources

The NUT (Network UPS Tools) home page: https://www.networkupstools.org/historic/v2.8.5/