When your UPS batteries get low, the operating system needs to be brought down cleanly. Also, the UPS load should be turned off so that all devices that are attached to it are forcibly rebooted.
Here are the steps that occur when a critical power event happens:
The UPS reaches low battery (a "critical" UPS), that is to say upsc displays:
ups.status: OB LB
The exact behavior depends on the specific device, and is related to:
The upsmon master notices and sets "FSD" - the "forced shutdown" flag to tell all slave systems that it will soon power down the load.
(If you have no slaves, skip to step 6)
upsmon slave systems see "FSD" and:
The upsmon master:
For this setup, we will be setting up our UPS master on a raspberry pi with slaves setup on a QNAP NAS and a Ubuntu Server.
Connect UPS using USP cable
$ sudo apt-get install nut |
$ vi /etc/nut/ups.conf |
Add the following config
[qnapups] driver = usbhid-ups port = auto desc = "Back-UPS ES 750" |
Configure upsd.conf
$ sudo vi /etc/nut/upsd.conf |
Add the following config:
LISTEN 0.0.0.0 3493 |
Update Credentials
$ sudo vi /etc/nut/upsd.users |
[admin] password = 123456 actions = SET instcmds = ALL [upsmon] password = 123456 upsmon master [deepthought] password = 123456 upsmon slave |
Update Nut.Conf
$ sudo vi /etc/nut/nut.conf |
Set Mode=netserver
MODE=netserver |
$ vi /etc/nut/upsmon.conf |
Add the following line
MONITOR qnapups@localhost 1 upsmon 123456 master FINALDELAY 5 |
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.
$ sudo upsdrvctl start |
$ sudo service nut-server restart |
$ sudo service nut-server status ● nut-server.service - Network UPS Tools - power devices information server Loaded: loaded (/lib/systemd/system/nut-server.service; enabled; vendor preset: enabled) Active: active (running) since Tue 2021-08-24 20:28:53 EDT; 7s ago Process: 12995 ExecStart=/sbin/upsd (code=exited, status=0/SUCCESS) Main PID: 12996 (upsd) Tasks: 1 (limit: 877) CGroup: /system.slice/nut-server.service └─12996 /lib/nut/upsd Aug 24 20:28:53 pihole systemd[1]: Starting Network UPS Tools - power devices information server... Aug 24 20:28:53 pihole upsd[12995]: fopen /var/run/nut/upsd.pid: No such file or directory Aug 24 20:28:53 pihole upsd[12995]: listening on 127.0.0.1 port 3493 Aug 24 20:28:53 pihole upsd[12995]: listening on ::1 port 3493 Aug 24 20:28:53 pihole upsd[12995]: listening on 127.0.0.1 port 3493 Aug 24 20:28:53 pihole upsd[12995]: Connected to UPS [homeups]: usbhid-ups-homeups Aug 24 20:28:53 pihole upsd[12995]: listening on ::1 port 3493 Aug 24 20:28:53 pihole upsd[12995]: Connected to UPS [homeups]: usbhid-ups-homeups Aug 24 20:28:53 pihole systemd[1]: Started Network UPS Tools - power devices information server. Aug 24 20:28:53 pihole upsd[12996]: Startup successful |
$ upsc qnapups@localhost $ upsc qnapups@192.168.1.52 battery.charge: 100 battery.charge.low: 10 ... ups.vendorid: 051d |
From the QNAP UI, open the control panel and navigate to External Sevices → UPS
Select Remote UPS Slave and enter the IP address of the master.
Click apply. The UPS information should now be updated. See screenshots below.
From a shell connection on the QNAP server, you can verify connection via the following command: (not required)
$ upsc qnapups@192.168.1.52 battery.charge: 100 ... ups.vendorid: 051d |
Install nut-client
$ sudo apt-get install nut-client |
Update nut-config
$ vi /etc/nut/nut.conf |
Set mode to netclient
MODE=netclient |
Update upsmon.conf
$ vi /etc/nut/upsmon.conf |
RUN_AS_USER root MONITOR qnapups@192.168.1.52 1 deepthought 123456 slave NOTIFYCMD /usr/sbin/upssched NOTIFYFLAG ONLINE WALL+EXEC NOTIFYFLAG ONBATT WALL+EXEC |
On our master we created a slave user called deepthought.
Edit the upssched.conf file
$ sudo vi /etc/nut/upssched.conf |
Set the following
CMDSCRIPT /etc/nut/upssched-cmd PIPEFN /var/run/nut/upssched.pipe LOCKFN /var/run/nut/upssched.lock # Timer to shutdown machine after 30 seconds AT ONBATT * START-TIMER onbattwarn 30 AT ONLINE * CANCEL-TIMER onbattwarn |
Create the Command Script
$ sudo vi /etc/nut/upssched-cmd |
Add the following content
case $1 in onbattwarn) logger -t upssched-cmd "Timer On Battery Warning has been triggered - Shutting Down!" wall "UPS timer expired: shutting down..." shutdown -h now ;; *) logger -t upssched-cmd "Unrecognized command: $1" ;; esac |
Restart nut client:
$ systemctl restart nut-client |
Get Status:
$ systemctl status nut-client |
● nut-monitor.service - Network UPS Tools - power device monitor and shutdown controller Loaded: loaded (/lib/systemd/system/nut-monitor.service; enabled; vendor preset: enabled) Active: active (running) since Wed 2021-08-25 13:11:09 EDT; 2s ago Process: 376582 ExecStart=/sbin/upsmon (code=exited, status=0/SUCCESS) Main PID: 376585 (upsmon) Tasks: 2 (limit: 19043) Memory: 1.1M CGroup: /system.slice/nut-monitor.service ├─376583 /lib/nut/upsmon └─376585 /lib/nut/upsmon Aug 25 13:11:09 deepthought systemd[1]: Starting Network UPS Tools - power device monitor and shutdown controller... Aug 25 13:11:09 deepthought upsmon[376582]: fopen /run/nut/upsmon.pid: No such file or directory Aug 25 13:11:09 deepthought upsmon[376582]: Using power down flag file /etc/killpower Aug 25 13:11:09 deepthought upsmon[376582]: UPS: qnapups@192.168.1.52 (slave) (power value 1) Aug 25 13:11:09 deepthought systemd[1]: nut-monitor.service: Can't open PID file /run/nut/upsmon.pid (yet?) after start: Operati> Aug 25 13:11:09 deepthought upsmon[376583]: Startup successful Aug 25 13:11:09 deepthought systemd[1]: nut-monitor.service: Supervising process 376585 which is not our child. We'll most likel> Aug 25 13:11:09 deepthought systemd[1]: Started Network UPS Tools - power device monitor and shutdown controller. |
Check Connection:
$ upsc qnapups@192.168.1.52 |
Installing NUT on Mac
> brew install nut ==> Downloading https://ghcr.io/v2/homebrew/core/nut/manifests/2.8.1 ######################################################################### 100.0% ==> Fetching nut ==> Downloading https://ghcr.io/v2/homebrew/core/nut/blobs/sha256:e89241f392bb9f ######################################################################### 100.0% ==> Pouring nut--2.8.1.arm64_sonoma.bottle.tar.gz Warning: The post-install step did not complete successfully You can try again using: brew postinstall nut ==> Caveats To start nut now and restart at login: brew services start nut Or, if you don't want/need a background service you can just run: /opt/homebrew/opt/nut/sbin/upsmon -D ==> Summary 🍺 /opt/homebrew/Cellar/nut/2.8.1: 94 files, 12MB ==> Running `brew cleanup nut`... |
Didn't work.....
Problem | Details |
---|---|
UPS Shutting Down | Sometimes the UPS shutdown for no reason. No power outage. cat /var/log/syslog |grep ups Mar 16 02:09:28 pihole upsmon[390]: UPS qnapups@localhost on battery Unplugging the power and querying the UPS showed a charge of 0! > upsc qnapups@localhost |grep battery
|
Get NUT status | sudo service nut-server status Mar 16 03:10:11 pihole upsd[374]: fopen /var/run/nut/upsd.pid: No such file or directory
|
Querying UPS | upsc qnapups@localhost $ upsc qnapups@192.168.1.52 battery.charge: 100 battery.charge.low: 10 ... ups.vendorid: 051d |
Reference | URL |
---|---|
Network UPS Tools User Manual | https://networkupstools.org/docs/user-manual.chunked/index.html |
Configuration | https://networkupstools.org/docs/user-manual.chunked/ar01s06.html |
UPSMON Man Page | https://networkupstools.org/docs/man/upsmon.conf.html |
NUT Introduction to Network UPS Tools - Configuration Examples | http://rogerprice.org/NUT/ConfigExamples.A5.pdf |
Raspberry Pi Home Server v2: Network UPS Tools | https://melgrubb.com/2016/12/11/rphs-v2-ups/ |