[Help] Connect to TOS7 UPS from esxi nut service [SOLVED]

[psychov]

Hi all.
Can You advice how to connect to TNAS UPS Server from ESXI7 via NUT?
ESXI says me that
2026-05-28T16:02:59.156Z upsmon[2136080]: UPS [192.168.1.5]: connect failed: Connection failure: Connection refused
2026-05-28T16:03:04.159Z upsmon[2136080]: UPS [192.168.1.5]: connect failed: Connection failure: Connection refused

This ip is bonded interface of F4-425+
In ESXI NUT I filled up right login password, but refused. What i'm doing wrong?

Thanks

[Gremlin]

iirc nut server on Tnas has it's own set of credentials not related to authorised users.

[psychov]

iirc nut server on Tnas has it's own set of credentials not related to authorised users.

Where I can find them?

[MikeZhang]

You may open TOS terminal and enter command line below and find from output.

Code: Select all

cat /etc/nut/upsd.users

[psychov]

I provided uspd.users with


and esxi nut with


but no result. What i'm, doing wrong?

[EriChan]

Regarding your issue where the ESXi host cannot connect to the TNAS UPS server, here is a detailed explanation and recommended steps:

Based on your feedback, the "Connection refused" error is a network-level problem, meaning the ESXi host cannot reach the NUT service port (3493) on your TNAS. This has no connection to the username and password configured in upsd.users.

In TOS 7, the NUT daemon (upsd) listens only on 127.0.0.1 (localhost) by default, and external queries are blocked by default unless you manually enable the required permissions.

Here are the steps to resolve this via the web UI:

• Log into your TOS 7 system via a web browser.

• Go to Control Panel > Hardware & Power > UPS.

• Ensure that "Enable TNAS UPS Server" is correctly checked.

• Be sure to add the exact IP address of your ESXi host to the "IP Addresses" list.

• Click Apply.

After applying the settings, TOS will automatically modify upsd.conf to have upsd listen on your bonded interface (192.168.1.5). Please try this and let me know if your ESXi host can connect successfully.

[psychov]

Regarding your issue where the ESXi host cannot connect to the TNAS UPS server, here is a detailed explanation and recommended steps:

Based on your feedback, the "Connection refused" error is a network-level problem, meaning the ESXi host cannot reach the NUT service port (3493) on your TNAS. This has no connection to the username and password configured in upsd.users.

In TOS 7, the NUT daemon (upsd) listens only on 127.0.0.1 (localhost) by default, and external queries are blocked by default unless you manually enable the required permissions.

Here are the steps to resolve this via the web UI:

• Log into your TOS 7 system via a web browser.

• Go to Control Panel > Hardware & Power > UPS.

• Ensure that "Enable TNAS UPS Server" is correctly checked.

• Be sure to add the exact IP address of your ESXi host to the "IP Addresses" list.

• Click Apply.

After applying the settings, TOS will automatically modify upsd.conf to have upsd listen on your bonded interface (192.168.1.5). Please try this and let me know if your ESXi host can connect successfully.

Big thanks for Your answer!
Doing exactly what You said. 192.168.1.4 - ip address of ESXi host

In ESXi's log see the following:


something going wrong =))

[EriChan]

To more effectively identify the root cause of the problem, we recommend that you contact our online technical support staff through the following link. We will guide you through troubleshooting steps to help resolve the related issues.

https://salesiq.zohopublic.com/signatur ... 97d0be8892

Thank you for your understanding and support!

[psychov]

In order to finish this issue - You simply need to add ups@ before the name or ip address of Yours UPS in ESXi options.


Big thanxx to Terramaster tech support.