upsmon.conf(5)
NAME
upsmon.conf - Configuration for Network UPS Tools upsmon
DESCRIPTION
This file's primary job is to define the systems that upsmon(8) will monitor and to tell it how to shut down the system when necessary. It will contain passwords, so keep it secure. Ideally, only the upsmon process should be able to read it. Additionally, other optional configuration values can be set in this file.
CONFIGURATION DIRECTIVES
DEADTIME seconds
upsmon allows a UPS to go missing for this many seconds before
declaring it "dead". The default is 15 seconds.
upsmon requires a UPS to provide status information every few
seconds (see POLLFREQ and POLLFREQALERT) to keep things updated. If
the status fetch fails, the UPS is marked stale. If it stays stale
for more than DEADTIME seconds, the UPS is marked dead.
A dead UPS that was last known to be on battery is assumed to have
changed to a low battery condition. This may force a shutdown if it
is providing a critical amount of power to your system. This seems
disruptive, but the alternative is barreling ahead into oblivion
and crashing when you run out of power.
Note: DEADTIME should be a multiple of POLLFREQ and POLLFREQALERT.
Otherwise, you'll have "dead" UPSes simply because upsmon isn't
polling them quickly enough. Rule of thumb: take the larger of the
two POLLFREQ values, and multiply by 3.
FINALDELAY seconds
When running in master mode, upsmon waits this long after sending
the NOTIFY_SHUTDOWN to warn the users. After the timer elapses, it
then runs your SHUTDOWNCMD. By default this is set to 5 seconds.
If you need to let your users do something in between those events,
increase this number. Remember, at this point your UPS battery is
almost depleted, so don't make this too big.
Alternatively, you can set this very low so you don't wait around
when it's time to shut down. Some UPSes don't give much warning for
low battery and will require a value of 0 here for a safe shutdown.
Note
If FINALDELAY on the slave is greater than HOSTSYNC on the
master, the master will give up waiting for the slave to
disconnect.
HOSTSYNC seconds
upsmon will wait up to this many seconds in master mode for the
slaves to disconnect during a shutdown situation. By default, this
is 15 seconds.
When a UPS goes critical (on battery + low battery, or "FSD":
forced shutdown), the slaves are supposed to disconnect and shut
down right away. The HOSTSYNC timer keeps the master upsmon from
sitting there forever if one of the slaves gets stuck.
This value is also used to keep slave systems from getting stuck if
the master fails to respond in time. After a UPS becomes critical,
the slave will wait up to HOSTSYNC seconds for the master to set
the FSD flag. If that timer expires, the slave will assume that the
master is broken and will shut down anyway.
This keeps the slaves from shutting down during a short-lived
status change to "OB LB" that the slaves see but the master misses.
MINSUPPLIES num
Set the number of power supplies that must be receiving power to
keep this system running. Normal computers have just one power
supply, so the default value of 1 is acceptable.
Large/expensive server type systems usually have more, and can run
with a few missing. The HP NetServer LH4 can run with 2 out of 4,
for example, so you'd set it to 2. The idea is to keep the box
running as long as possible, right?
Obviously you have to put the redundant supplies on different UPS
circuits for this to make sense! See big-servers.txt in the docs
subdirectory for more information and ideas on how to use this
feature.
Also see the section on "power values" in upsmon(8).
MONITOR system powervalue username password type
Each UPS that you need to be monitor should have a MONITOR line.
Not all of these need supply power to the system that is running
upsmon. You may monitor other systems if you want to be able to
send notifications about status changes on them.
You must have at least one MONITOR directive in upsmon.conf.
system is a UPS identifier. It is in this form:
<upsname>[@<hostname>[:<port>]]
The default hostname is "localhost". Some examples:
* "su700@mybox" means a UPS called "su700" on a system called
"mybox". This is the normal form.
* "fenton@bigbox:5678" is a UPS called "fenton" on a system called
"bigbox" which runs upsd(8) on port "5678".
powervalue is an integer representing the number of power supplies that
the UPS feeds on this system. Most normal computers have one power
supply, and the UPS feeds it, so this value will be 1. You need a very
large or special system to have anything higher here.
You can set the powervalue to 0 if you want to monitor a UPS that
doesn't actually supply power to this system. This is useful when you
want to have upsmon do notifications about status changes on a UPS
without shutting down when it goes critical.
The username and password on this line must match an entry in that
system's upsd.users(5). If your username is "monmaster" and your
password is "blah", the MONITOR line might look like this:
MONITOR myups@bigserver 1 monmaster blah master
Meanwhile, the upsd.users on bigserver would look like this:
[monmaster]
password = blah
upsmon master # (or slave)
The type refers to the relationship with upsd(8). It can be either
"master" or "slave". See upsmon(8) for more information on the meaning
of these modes. The mode you pick here also goes in the upsd.users
file, as seen in the example above.
NOCOMMWARNTIME seconds
upsmon will trigger a NOTIFY_NOCOMM after this many seconds if it
can't reach any of the UPS entries in this configuration file. It
keeps warning you until the situation is fixed. By default this is
300 seconds.
NOTIFYCMD command
upsmon calls this to send messages when things happen.
This command is called with the full text of the message as one
argument. The environment string NOTIFYTYPE will contain the type
string of whatever caused this event to happen.
If you need to use upssched(8), then you must make it your
NOTIFYCMD by listing it here.
Note that this is only called for NOTIFY events that have EXEC set
with NOTIFYFLAG. See NOTIFYFLAG below for more details.
Making this some sort of shell script might not be a bad idea. For
more information and ideas, see docs/scheduling.txt
Remember, this command also needs to be one element in the
configuration file, so if your command has spaces, then wrap it in
quotes.
NOTIFYCMD "/path/to/script --foo --bar"
This script is run in the background---that is, upsmon forks before
it calls out to start it. This means that your NOTIFYCMD may have
multiple instances running simultaneously if a lot of stuff happens
all at once. Keep this in mind when designing complicated
notifiers.
NOTIFYMSG type message
upsmon comes with a set of stock messages for various events. You
can change them if you like.
NOTIFYMSG ONLINE "UPS %s is getting line power"
NOTIFYMSG ONBATT "Someone pulled the plug on %s"
Note that %s is replaced with the identifier of the UPS in
question.
The message must be one element in the configuration file, so if it
contains spaces, you must wrap it in quotes.
NOTIFYMSG NOCOMM "Someone stole UPS %s"
Possible values for type:
ONLINE
UPS is back online
ONBATT
UPS is on battery
LOWBATT
UPS is on battery and has a low battery (is critical)
FSD
UPS is being shutdown by the master (FSD = "Forced Shutdown")
COMMOK
Communications established with the UPS
COMMBAD
Communications lost to the UPS
SHUTDOWN
The system is being shutdown
REPLBATT
The UPS battery is bad and needs to be replaced
NOCOMM
A UPS is unavailable (can't be contacted for monitoring)
NOTIFYFLAG type flag[+flag][+flag]...
By default, upsmon sends walls global messages to all logged in
users) via /bin/wall and writes to the syslog when things happen.
You can change this.
Examples:
NOTIFYFLAG ONLINE SYSLOG
NOTIFYFLAG ONBATT SYSLOG+WALL+EXEC
Possible values for the flags:
SYSLOG
Write the message to the syslog
WALL
Write the message to all users with /bin/wall
EXEC
Execute NOTIFYCMD (see above) with the message
IGNORE
Don't do anything
If you use IGNORE, don't use any other flags on the same line.
POLLFREQ seconds
Normally upsmon polls the upsd(8) server every 5 seconds. If this
is flooding your network with activity, you can make it higher. You
can also make it lower to get faster updates in some cases.
There are some catches. First, if you set the POLLFREQ too high,
you may miss short-lived power events entirely. You also risk
triggering the DEADTIME (see above) if you use a very large number.
Second, there is a point of diminishing returns if you set it too
low. While upsd normally has all of the data available to it
instantly, most drivers only refresh the UPS status once every 2
seconds. Polling any more than that usually doesn't get you the
information any faster.
POLLFREQALERT seconds
This is the interval that upsmon waits between polls if any of its
UPSes are on battery. You can use this along with POLLFREQ above to
slow down polls during normal behavior, but get quicker updates
when something bad happens.
This should always be equal to or lower than the POLLFREQ value. By
default it is also set 5 seconds.
The warnings from the POLLFREQ entry about too-high and too-low
values also apply here.
POWERDOWNFLAG filename
upsmon creates this file when running in master mode when the UPS
needs to be powered off. You should check for this file in your
shutdown scripts and call upsdrvctl shutdown if it exists.
This is done to forcibly reset the slaves, so they don't get stuck
at the "halted" stage even if the power returns during the shutdown
process. This usually does not work well on contact-closure UPSes
that use the genericups driver.
See the shutdown.txt file in the docs subdirectory for more
information.
RBWARNTIME seconds
When a UPS says that it needs to have its battery replaced, upsmon
will generate a NOTIFY_REPLBATT event. By default, this happens
every 43200 seconds (12 hours).
If you need another value, set it here.
RUN_AS_USER username
upsmon normally runs the bulk of the monitoring duties under
another user ID after dropping root privileges. On most systems
this means it runs as "nobody", since that's the default from
compile-time.
The catch is that "nobody" can't read your upsmon.conf, since by
default it is installed so that only root can open it. This means
you won't be able to reload the configuration file, since it will
be unavailable.
The solution is to create a new user just for upsmon, then make it
run as that user. I suggest "nutmon", but you can use anything that
isn't already taken on your system. Just create a regular user with
no special privileges and an impossible password.
Then, tell upsmon to run as that user, and make upsmon.conf
readable by it. Your reloads will work, and your config file will
stay secure.
This file should not be writable by the upsmon user, as it would be
possible to exploit a hole, change the SHUTDOWNCMD to something
malicious, then wait for upsmon to be restarted.
SHUTDOWNCMD command
upsmon runs this command when the system needs to be brought down.
If it is a slave, it will do that immediately whenever the current
overall power value drops below the MINSUPPLIES value above.
When upsmon is a master, it will allow any slaves to log out before
starting the local shutdown procedure.
Note that the command needs to be one element in the config file.
If your shutdown command includes spaces, then put it in quotes to
keep it together, i.e.:
SHUTDOWNCMD "/sbin/shutdown -h +0"
CERTPATH certificate file or database
When compiled with SSL support, you can enter the certificate path
here.
With NSS:
Certificates are stored in a dedicated database (splitted in 3
files). Specify the path of the database directory.
With OpenSSL:
Directory containing CA certificates in PEM format, used to
verify the server certificate presented by the upsd server. The
files each contain one CA certificate. The files are looked up
by the CA subject name hash value, which must hence be
available.
CERTIDENT certificate name database password
When compiled with SSL support with NSS, you can specify the
certificate name to retrieve from database to authenticate itself
and the password required to access certificate related private
key.
CERTHOST hostname certificate name certverify forcessl
When compiled with SSL support with NSS, you can specify security
directive for each server you can contact.
Each entry maps server name with the expected certificate name and
flags indicating if the server certificate is verified and if the
connection must be secure.
CERTVERIFY 0 | 1
When compiled with SSL support, make upsmon verify all connections
with certificates.
Without this, there is no guarantee that the upsd is the right
host. Enabling this greatly reduces the risk of man-in-the-middle
attacks. This effectively forces the use of SSL, so don't use this
unless all of your upsd hosts are ready for SSL and have their
certificates in order.
When compiled with NSS support of SSL, can be overriden for host
specified with a CERTHOST directive.
FORCESSL 0 | 1
When compiled with SSL, specify that a secured connection must be
used to communicate with upsd.
If you don't use CERTVERIFY 1, then this will at least make sure
that nobody can sniff your sessions without a large effort. Setting
this will make upsmon drop connections if the remote upsd doesn't
support SSL, so don't use it unless all of them have it running.
When compiled with NSS support of SSL, can be overriden for host
specified with a CERTHOST directive.
SEE ALSO
upsmon(8), upsd(8), nutupsdrv(8). Internet resources: The NUT (Network UPS Tools) home page: http://www.networkupstools.org/
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