@olivierlambert
I wrote down the to-dos. You can use it for the official docs if you like! When you have questions, just answer on this Post.

Network UPS Tools
Installation on XCP-ng Host

At first: Connect your UPS.
Then run this commands to install NUT:

yum update

yum –enablerepo=* install epel-release

yum install nut

yum install nut-client

cd /etc/ups

wget https://github.com/serrc-techops/NUT-Configuration/blob/master/slave/xen/xen-shutdown.sh

chmod +x xen-shutdown.sh

Important Commands

• upsc apcups (check UPS connection)

• systemctl restart nut-server
  (NUT-server reboot) | (Use this to apply configuration changes and to connect the UPS after System startup)

• systemctl restart nut-monitor (NUT-monitor restart)

• nut-scacnner -U (shows connected devices)

Configure the files stored in /etc/ups like this:
upsmon.conf

RUN_AS_USER root
MONITOR apcups@localhost 1 admin [PASSWORD] master
SHUTDOWNCMD „/etc/ups/xen-shutdown.sh“

nut.conf

MODE=netserver

ups.conf

pollinterval = 1
maxretry = 3
[apcups]
driver = usbhid-ups 
#->when you use USB devices
port = auto
desc = „[NAME]“
vendorid = [VENDORID]
productid = [PRODUCTID]
serial = „[SERIALNO]“

upsd.conf

LISTEN 0.0.0.0 3493

upsd.users

[admin]
password = [PASSWORD]
actions = set
actions= fsd
instcmds = ALL

Finish config Changes

systemctl restart nut-server
systemctl restart nut-monitor

Finished
Good to know: You can now also connect to your NUT server via the pfSense plugin by using the credentials in uspd.users to have a gui for your UPS. To do this you have to open up Port 3493 on your host.
Run this command to open the Port:

iptables -I INPUT -p tcp -m tcp --dport 3493 -j ACCEPT

Then save your changes to a config file and adjust Year, Month and Day in the config name. In my case it's the 22th of december in 2022:

iptables-save > /etc/sysconfig/iptables
mkdir /etc/iptables/
iptables-save > /etc/iptables/rules_2022-12-22_INPUT_ACCEPT_3493_NUT.v4 --> Optional, extra saving for Backups.

I recommend using this convention of naming your rule files. Its a lot easier to track your changes and to restore files.

@olivierlambert Oh man, only saw this answer because I went back to my old post. I will do a full guide when I have some time and send it to you.

I found this post:
https://voice1.me/automated-shutdown-xenserver-7-x-with-network-ups-tool/

I just used the Driver type for USB: usbhid-ups

You can find the correct driver type for your system here:
https://networkupstools.org/stable-hcl.html

Here is the guide for USB (partly copied from the article):

IMPORTANT: The way I made is is not recommend! Your pfSense should normally not run on a VM using this method but it still works. It's recommended to use a physical pfSense to perform this setup.

Requirement:

• a VM running pfSense
• all VMs on your XCP-ng host have to run guest gtilities.
• a USP with USB Connection
• XCP-ng Center

1. Connecting the USP to a VM via USB

• Plug-in the USP via USB into the Server
• Enable USB-passthrough in the USB Tab of your Host (XCP-ng Center)
• Shutdown the pfSense, attach the USB device to the pfSense VM in the Properties Tab of the VM
• Start the VM

2. Installing NUT
   If you are using pfSense, you can install nut from the Package Manager. Once installed you will be able to access the setup from Services > UPS.

• Select “Local USB” from the UPS Type and provide a UPS Name.
• add this to your uspd.conf:

ACL all 0.0.0.0/0
ACCEPT all

• add this to your uspd.users:

[(YOUR USERNAME)]
password = (YOUR PASSWORD)
allowfrom = all
instcmds = ALL

Attention! The username has to be written with the brackets! ie: [admin]

• click on save and pfSense should now detect your UPS and give you its information in the UPS Dashboard.

3. Configure the XCP-ng host as NUT slave (pfSense is master)

• By default the built in repository does not have the required library, so we need to enable the epel repository before we can install the nut-client

yum --enablerepo=* install epel-release

yum --enablerepo=* install nut-client.x86_64

• Now we need to tell NUT that we want it to listen to an existing NUT Server, in other words, we want to be a “client”.

nano /etc/ups/nut.conf
MODE=netclient

• Now that NUT knows it will be retrieving information from another network server, we need to tell it what network server to “MONITOR”. You will need to modify only 2 variables in the file /etc/ups/upsmon.conf but take a look around because you can tweak how the NUT Client responds by modifying the settings in this file. For now, lets just tell NUT where to retrieve its information from.

nano /etc/ups/upsmon.conf
MONITOR (NAME OF YOUR UPS)@(PFSENSE IP) 1 (USERNAME) (PASSWORD) slave
SHUTDOWNCMD "/etc/ups/xen-shutdown.sh"

• You probably already have a SHUTDOWNCMD in your configuration Just add a comment “#” to the start of the line and add the one provided above. Speaking of the SHUTDOWNCMD, you will notice that we are calling a specific script. This script can be downloaded here.

cd /etc/ups
wget https://raw.githubusercontent.com/serrc-techops/NUT-Configuration/master/slave/xen/xen-shutdown.sh
chmod +x xen-shutdown.sh

!!! I wasn't able to perform the next step because the service started to fail afterwards!!!
The shutdown still works. I try to figure out a solution and add it here.

So on a power failure, the NUT Master sends a message to all subscribed NUT Clients, and the NUT Client shuts down based on its configuration. Wonderful Now our Xen Guests can shutdown, and so can our server. But what happens when we power them back up? We need to make sure that NUT starts on our XenServer.

• To do so create a new file, /etc/systemd/system/nut-monitor.service and add the following to it.

[Unit]
Description=Network UPS Tools - XenServer Shutdown
After=local-fs.target network.target
 
[Service]
ExecStart=/usr/sbin/upsmon
PIDFile=/run/nut/upsmon.pid
Type=forking
 
[Install]
WantedBy=multi-user.target

Now that we have a system startup script in place, lets make sure it runs on start up.

systemctl enable nut-monitor.service
systemctl daemon-reload
systemctl start nut-monitor

4. Testing shutdown

• Execute this command in the Shell of your pfSense:
  This will simulate a power cut!!!

upsmon -c fsd

If you have any questions ask me below.

There is one problem: you have to reattach the USB to the VM after every host reboot!

@Andrew okay now I understand! Thanks a lot!!!

Hey there,
I encountered following:
My Full Backup interval is 28 and my Backup Retention is 29. But after the new Full Backup interval began and the new full backup was created the next delta backup seems to point the old full Backup. Why do I think so?

• The old Full Backup was not deleted on the remote although it dissappeared in XOA.
• The latest change date of the old full Backup is AFTER the new full backup.

Remote Files:

XOA available Restore Backups

Is this something to worry about? I'm afraid of deleting the old Full Backup.
If this is an error: How to solve this?

@odeawan Sure but you need a nut server. When you use the XCP-NG Server as a client you have to install the nut server on a different system. You can't install the nut server on a vm on the same host because the nut server must be installed on a system to shut down last.
So running this scenario is the most redundant and efficient way.

@Gheppy thanks!

Hey there,
How should I configure the Backup Retention when using Delta Backup and a Full Backup Interval of 20? When I set the Backup Retention to 21 and the Full Backup gehts deleted after the 22th Backup: Can I restore the Delta Backups with the Full Backup taken AFTER the Delta Backups or will all Backups in the chain before the new Full Backup be useless after deleting the initial Full Backup?

Greetings and thanks in advance.

@lknite Glad I could help and I agree.

@olivierlambert
I wrote down the to-dos. You can use it for the official docs if you like! When you have questions, just answer on this Post.

Network UPS Tools
Installation on XCP-ng Host

At first: Connect your UPS.
Then run this commands to install NUT:

yum update

yum –enablerepo=* install epel-release

yum install nut

yum install nut-client

cd /etc/ups

wget https://github.com/serrc-techops/NUT-Configuration/blob/master/slave/xen/xen-shutdown.sh

chmod +x xen-shutdown.sh

Important Commands

• upsc apcups (check UPS connection)

• systemctl restart nut-server
  (NUT-server reboot) | (Use this to apply configuration changes and to connect the UPS after System startup)

• systemctl restart nut-monitor (NUT-monitor restart)

• nut-scacnner -U (shows connected devices)

Configure the files stored in /etc/ups like this:
upsmon.conf

RUN_AS_USER root
MONITOR apcups@localhost 1 admin [PASSWORD] master
SHUTDOWNCMD „/etc/ups/xen-shutdown.sh“

nut.conf

MODE=netserver

ups.conf

pollinterval = 1
maxretry = 3
[apcups]
driver = usbhid-ups 
#->when you use USB devices
port = auto
desc = „[NAME]“
vendorid = [VENDORID]
productid = [PRODUCTID]
serial = „[SERIALNO]“

upsd.conf

LISTEN 0.0.0.0 3493

upsd.users

[admin]
password = [PASSWORD]
actions = set
actions= fsd
instcmds = ALL

Finish config Changes

systemctl restart nut-server
systemctl restart nut-monitor

Finished
Good to know: You can now also connect to your NUT server via the pfSense plugin by using the credentials in uspd.users to have a gui for your UPS. To do this you have to open up Port 3493 on your host.
Run this command to open the Port:

iptables -I INPUT -p tcp -m tcp --dport 3493 -j ACCEPT

Then save your changes to a config file and adjust Year, Month and Day in the config name. In my case it's the 22th of december in 2022:

iptables-save > /etc/sysconfig/iptables
mkdir /etc/iptables/
iptables-save > /etc/iptables/rules_2022-12-22_INPUT_ACCEPT_3493_NUT.v4 --> Optional, extra saving for Backups.

I recommend using this convention of naming your rule files. Its a lot easier to track your changes and to restore files.

@olivierlambert Oh man, only saw this answer because I went back to my old post. I will do a full guide when I have some time and send it to you.

@peek said in Performing automated shutdown during a power failure using a USB-UPS with NUT - XCP-ng 8.2:

yum --enablerepo=* install nut.x86_64

This video solved it for me (altough its in german)
YouTube Tut

Thread can be closed.

@aimdev thanks for the information!