Ubuntu Manpage: ups.conf - UPS definitions for Network UPS Tools

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, e.g. for troubleshooting a
deployment, 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.