NetXMS Support Forum

Quote from: Filipp Sudanov on January 23, 2026, 03:33:01 PMThe reason seems to be with the framework used to build the GUI. Here's Anthropic's Claude's comment on this, pls give us update if any of this helps:

● This is a SWT/GTK compatibility crash on ARM64 (Raspberry Pi 5). The segfault occurs in GTK's native code when rendering the         
  Infrastructure view. Here are potential fixes:                                                                                       
                                                                                                                                       
  Quick Fixes to Try                                                                                                                   
                                                                                                                                       

Hi Filipp,

Thanks for the feedback. Given that I am using KDE then that may further explain the issues as there is not much by way of GTK installed on this machine, though the core libraries are present.

I will try the suggestions and revert.

Best,

Alex

The reason seems to be with the framework used to build the GUI. Here's Anthropic's Claude's comment on this, pls give us update if any of this helps:

● This is a SWT/GTK compatibility crash on ARM64 (Raspberry Pi 5). The segfault occurs in GTK's native code when rendering the         
  Infrastructure view. Here are potential fixes:                                                                                       
                                                                                                                                       
  Quick Fixes to Try                                                                                                                   
                                                                                                                                       
  1. Force GTK3 settings                                                                                                               
                                                                                                                                       
  export SWT_GTK3=1                                                                                                                   
  export GDK_BACKEND=x11                                                                                                               
  java -jar nxmc-5.2.8-standalone.jar                                                                                                 
                                                                                                                                       
  2. Disable GTK overlay scrollbars (likely culprit given "Negative content width" errors)                                             
                                                                                                                                       
  export GTK_OVERLAY_SCROLLING=0                                                                                                       
  java -jar nxmc-5.2.8-standalone.jar                                                                                                 
                                                                                                                                       
  3. Try a simpler GTK theme                                                                                                           
                                                                                                                                       
  export GTK_THEME=Adwaita                                                                                                             
  java -jar nxmc-5.2.8-standalone.jar                                                                                                 
                                                                                                                                       
  4. All environment variables combined                                                                                               
                                                                                                                                       
  export SWT_GTK3=1                                                                                                                   
  export GDK_BACKEND=x11                                                                                                               
  export GTK_OVERLAY_SCROLLING=0                                                                                                       
  export GTK_THEME=Adwaita                                                                                                             
  java -jar nxmc-5.2.8-standalone.jar                                                                                                 
                                                                                                                                       
  5. Try with additional JVM flags                                                                                                     
                                                                                                                                       
  java -Dorg.eclipse.swt.internal.gtk.disablePrinting=true \                                                                           
       -Dorg.eclipse.swt.internal.gtk.noFocusHack=true \                                                                               
       -jar nxmc-5.2.8-standalone.jar                                                                                                 
                                                                                                                                       
  Root Cause                                                                                                                           
                                                                                                                                       
  The crash happens in g_type_check_instance_is_a which indicates GTK is receiving an invalid widget reference. The "Negative content 
  width -1" warnings suggest the scrollbar widget calculation fails before the crash. This is a known issue with:                     
  - SWT on ARM64 Linux                                                                                                                 
  - Certain GTK3 versions with KDE/Plasma (GTK apps under Qt-based desktop)                                                           
  - Overlay scrollbars in newer GTK versions                                                                                           
                                                                                                                                       
  If Above Doesn't Work                                                                                                               
                                                                                                                                       
  1. Try Wayland instead of X11 (or vice versa):                                                                                       
  export GDK_BACKEND=wayland                                                                                                           
  2. Install older GTK3:                                                                                                               
  Debian Trixie (testing) may have a bleeding-edge GTK that has compatibility issues.                                                 
  3. Use the Web UI instead - avoids native SWT/GTK entirely by running NXMC in a browser.                                             
  4. Report to NetXMS with the workaround that helped (or didn't) so they can investigate the SWT version bundled in the standalone JAR
   for ARM64.     

I have also tried to update java to openjdk-25-jre

Its better, I could use the client for about 2-3 minutes, then it crashed.

# A fatal error has been detected by the Java Runtime Environment:
#
#  SIGSEGV (0xb) at pc=0x00007ffe43d70648, pid=144722, tid=144723
#
# JRE version: OpenJDK Runtime Environment (25.0.1+8) (build 25.0.1+8-Debian-1deb13u1)
# Java VM: OpenJDK 64-Bit Server VM (25.0.1+8-Debian-1deb13u1, mixed mode, sharing, tiered, compressed oops, compressed class ptrs, g1 gc, linux-aarch64)
# Problematic frame:
# C  [libgtk-3.so.0+0x5d0648]  gtk_widget_is_sensitive+0x28
#
# Core dump will be written. Default location: Core dumps may be processed with "/usr/lib/systemd/systemd-coredump %P %u %g %s %t %c %h %d %F" (or dumping to /home/alex/Downloads/core.144722)
#
# An error report file with more information is saved as:
# /home/alex/Downloads/hs_err_pid144722.log
[204.802s][warning][os] Loading hsdis library failed
#
# If you would like to submit a bug report, please visit:
#   https://bugs.debian.org/openjdk-25
# The crash happened outside the Java Virtual Machine in native code.
# See problematic frame for where to report the bug.
#
Aborted (core dumped)



For completeness here is a config that I have tried, on the pve host:

apt install netxms-agent-vmgr
 apt install netxms-agent-vmgr
The following packages were automatically installed and are no longer required:
  libsnmp-base  libsnmp40t64  proxmox-kernel-6.17.2-2-pve-signed
Use 'apt autoremove' to remove them.

Installing:
  netxms-agent-vmgr

Installing dependencies:
  libvirt-common  libvirt-l10n  libvirt0

Summary:
  Upgrading: 0, Installing: 4, Removing: 0, Not Upgrading: 5
  Download size: 4,810 kB
  Space needed: 29.9 MB / 15.7 GB available

Continue? [Y/n] y
Get:2 http://deb.debian.org/debian trixie/main amd64 libvirt-common amd64 11.3.0-3+deb13u2 [215 kB]
Get:3 http://deb.debian.org/debian trixie/main amd64 libvirt0 amd64 11.3.0-3+deb13u2 [1,605 kB]
Get:4 http://deb.debian.org/debian trixie/main amd64 libvirt-l10n all 11.3.0-3+deb13u2 [2,932 kB]
Get:1 https://packages.netxms.org/debian trixie/main amd64 netxms-agent-vmgr amd64 5.2.8-1+trixie [56.8 kB]
Fetched 4,810 kB in 3s (1,517 kB/s)                                             
Selecting previously unselected package libvirt-common.
(Reading database ... 76467 files and directories currently installed.)
Preparing to unpack .../libvirt-common_11.3.0-3+deb13u2_amd64.deb ...
Unpacking libvirt-common (11.3.0-3+deb13u2) ...
Selecting previously unselected package libvirt0:amd64.
Preparing to unpack .../libvirt0_11.3.0-3+deb13u2_amd64.deb ...
Unpacking libvirt0:amd64 (11.3.0-3+deb13u2) ...
Selecting previously unselected package libvirt-l10n.
Preparing to unpack .../libvirt-l10n_11.3.0-3+deb13u2_all.deb ...
Unpacking libvirt-l10n (11.3.0-3+deb13u2) ...
Selecting previously unselected package netxms-agent-vmgr:amd64.
Preparing to unpack .../netxms-agent-vmgr_5.2.8-1+trixie_amd64.deb ...
Unpacking netxms-agent-vmgr:amd64 (5.2.8-1+trixie) ...
Setting up libvirt-common (11.3.0-3+deb13u2) ...
Setting up libvirt0:amd64 (11.3.0-3+deb13u2) ...
Setting up netxms-agent-vmgr:amd64 (5.2.8-1+trixie) ...
Setting up libvirt-l10n (11.3.0-3+deb13u2) ...
Processing triggers for libc-bin (2.41-12+deb13u1) ...
root@pve01:~#

#============================================================================
# NetXMS Agent Configuration File for Proxmox VE Hypervisor Monitoring
#============================================================================
[vmgr]
host = pve01

[vmgr:pve01]
Url = qemu:///system

Log file
2026.01.23 14:45:55.950 *E* [vmgr               ] Failed to connect socket to '/var/run/libvirt/libvirt-sock': No such file or directory
2026.01.23 14:45:55.950 *W* [vmgr               ] Unable to add host connection "pve01" with URL "qemu:///system"
2026.01.23 14:45:55.950 *W* [vmgr               ] No connections defined, VMGR subagent will not start

Yes I see that the libvirt process is not running but I am reluctant to run it due to the various comments out there about libvirt issues with proxmox

The error is "Data too long for column 'lldp_id' at row 1".

NetXMS found some new snmp device, for some reason the value for lldp_id column is too long and is not fitting into 255 chars.

It would be good to understand which exactly is that device on your network. You can enable debug for poll.discovery tag by issuing

debug poll.discovery 6

in Tools -> Server Debug Console. Then you should see some IP address being polled prior to the SQL error in the log. Once you know the IP address, please do a walk for 1.0.8802.1.1.2.1.3 branch and share the output. You can use nxsnmpwalk for that

We have this information in Audit log, but if you need it in Event Log - there's Hook::login script in script library that you can use for that. Make sure that this script returns true, otherwise it will prevent users from logging in.

To see what attributes are available in this script you can try this - it will log details to server log:

for (a : $user.__class.attributes) trace(0, "$user." .. a .. " = " .. $user.__get(a));
for (a : $session.__class.attributes) trace(0, "$session." .. a .. " = " .. $session.__get(a));
return true;

Then you can use PostEvent() or PostEventEx() to create the event (https://netxms.org/documentation/nxsl-latest/#func-postevent), drop us a line if you need more help with scripting.

Can you do a tcpdump capture with this command:
tcpdump -s 0 -w snmp-exchange.pcap host = DEVICE_IP

We are interested in querying one problematic OID - first from nxsnmpget and then from NetXMS. Command will produce a file that can be opened using Wireshark. Please share the file.

Submitted bug report:

NX-2909

Thank you,

I have now discovered that unfortunately proxmox does not use libvirt and installing it on the host is risky as it can clash with the underlying qemu lxc tech that proxmox uses. Proxmox strongly advises against doing this.

So at this point we can say that NetXMS does NOT support Proxmox monitoring using the documented Hypervisor monitoring methods.

It may be possible to do via the proxmox API which is the proxmox approved method.

The netxms agent does monitor the usual proxmox host details just fine, but I am looking to collect the metrics about the vms / containers etc.

The documentation should be updated to reflect this, and also note that there seems to be a separate subagent package for Xen.

Where do we specify them so we can choose them in the dropdown?