ZBX_NOTSUPPORTED error even with direct UserParameter in zabbix_agentd.conf (v6.2.7)

[pilotnite]

Hello all,

I'm running into a strange issue with Zabbix Agent 6.2.7 compiled with --enable-agent --sysconfdir=/etc on an embedded Linux system (Yocto-based).

I'm trying to test a simple UserParameter, but even with the key defined directly in /etc/zabbix/zabbix_agentd.conf, it returns unsupported:
# grep -i UserParameter /etc/zabbix/zabbix_agentd.conf
UserParameter=test.hello,echo hello

# zabbix_agentd -t test.hello
test.hello [m|ZBX_NOTSUPPORTED] [Unsupported item key.]

Agent startup logs look clean:
Zabbix Agent 6.2.7 (revision d7e8df54d76)
using configuration file: /etc/zabbix/zabbix_agentd.conf
...
agent #0 started [main process]
...
agent #5 started [active checks #1]


I’ve verified:

• Agent is running with the correct config: /etc/zabbix/zabbix_agentd.conf
• The UserParameter is defined directly in that file
• Permissions on the file are correct
• No duplicate keys exist
• No related errors appear in /tmp/zabbix_agentd.log

I've also tried defining test.hello inside zabbix_agentd.d/test.conf with Include=/etc/zabbix/zabbix_agentd.d/*.conf enabled — same result: ZBX_NOTSUPPORTED.

Would really appreciate any insight into what else could cause this behavior, especially when the key is defined in the main config itself.

Thanks in advance!

Cheers,
Nitesh

[pilotnite]

Hi Markku,

Just wanted to follow up — it turns out the UserParameter= is working correctly on its own.

In my case, I simply needed to specify the configuration file explicitly when testing via the command line using zabbix_agentd. Here's a working example:

# zabbix_agentd -t modem.lte.rssi -c /etc/zabbix/zabbix_agentd.conf modem.lte.rssi
[t|-78.00]

So the configuration and UserParameter logic are functioning as expected; the issue was only related to manual testing without the -c flag.

Thanks again for your guidance — much appreciated!

Best regards,
Nitesh

[Markku]

In the manual it says that the command is a "shell command". Is it possible that your system has some limitations on starting shells?

Maybe increase the agent log level (in runtime or with DebugLevel) and test getting the item with zabbix_get, then you will get more information about the agent when it processes the item. Also test getting an undefined item like "test.hello2", if it gives you different output and leads you somewhere.

Also "zabbix_agentd --print" should be checked that it contains your UserParameter item.

$ /usr/sbin/zabbix_agentd --print | grep hello
test.hello                                    [t|hello]

Markku

[pilotnite]

Hi Markku,

Thanks again for your help and suggestions.

I wanted to share my findings after further testing the UserParameter behavior:

The Zabbix agent is correctly configured with the following line in /etc/zabbix/zabbix_agentd.conf:
UserParameter=test.hello,/bin/echo hello

However, when I run:
zabbix_agentd -t test.hello
I receive:
[m|ZBX_NOTSUPPORTED] [Unsupported item key.]

But if I explicitly pass the config file, it works as expected:
zabbix_agentd -t test.hello -c /etc/zabbix/zabbix_agentd.conf
=> [t|hello]
zabbix_agentd -t test.hello2 -c /etc/zabbix/zabbix_agentd.conf
=> [m|ZBX_NOTSUPPORTED] [Unsupported item key.]
zabbix_agentd -c /etc/zabbix/zabbix_agentd.conf --print | grep hello
=> test.hello [t|hello]

This indicates that, despite the agent being installed with the correct config path (/etc/zabbix/zabbix_agentd.conf), it does not pick it up unless -c is explicitly specified.

For reference, the systemd service is correctly running the agent with the -c option:
# systemctl status zabbix-agent
* zabbix-agent.service - Zabbix Monitor Agent
Loaded: loaded (/lib/systemd/system/zabbix-agent.service; enabled; vendor preset: enabled)
Active: active (running) since Tue 2025-07-29 02:22:02 UTC; 1 day 14h ago
Main PID: 475 (zabbix_agentd)
Tasks: 6 (limit: 1042)
Memory: 10.1M
CGroup: /system.slice/zabbix-agent.service
|- 475 /usr/sbin/zabbix_agentd -c /etc/zabbix/zabbix_agentd.conf
|- 476 "/usr/sbin/zabbix_agentd: collector [idle 1 sec]"
|- 477 "/usr/sbin/zabbix_agentd: listener #1 [waiting for connection]"
|- 478 "/usr/sbin/zabbix_agentd: listener #2 [waiting for connection]"
|- 479 "/usr/sbin/zabbix_agentd: listener #3 [waiting for connection]"
`- 480 "/usr/sbin/zabbix_agentd: active checks #1 [idle 1 sec]"

Is there anything else you’d recommend checking? Your help is much appreciated.

Cheers,
Nitesh

[Markku]

Ok, so you have demonstrated that your zabbix_agentd does not read /etc/zabbix/zabbix_agentd.conf by default (for any reason), and that's why the -t test does not work without explicitly setting the config file location.

But does your item work? In a Zabbix item configuration, or by using zabbix_get.

Markku

[pilotnite]

Hello Markku,

Thank you for your feedback.

Yes, as an alternative option I end up running a bash script using `zabbix_sender` like:

  /usr/bin/zabbix_sender -z server_ip -s host -k modem.lte.rssi -o "$RSSI"

Cheers,
Nitesh

[pilotnite]

Forgot to add:

# zabbix_get -s 127.0.0.1 -p 10050 -k test.hello

hello
# zabbix_get -s 127.0.0.1 -p 10050 -k test.hello2

ZBX_NOTSUPPORTED: Unsupported item key.

[pilotnite]

Hi Markku,

Just wanted to follow up — it turns out the UserParameter= is working correctly on its own.

In my case, I simply needed to specify the configuration file explicitly when testing via the command line using zabbix_agentd. Here's a working example:

# zabbix_agentd -t modem.lte.rssi -c /etc/zabbix/zabbix_agentd.conf modem.lte.rssi
[t|-78.00]

So the configuration and UserParameter logic are functioning as expected; the issue was only related to manual testing without the -c flag.

Thanks again for your guidance — much appreciated!

Best regards,
Nitesh

[Markku]

Thanks for following up.

Based on the examples in https://www.zabbix.com/documentation...lation/install, I'd guess your agent is (without -c) expecting the config file to be at /etc/zabbix_agentd.conf.

Markku