NSX Host Configuration Fails during VCF 9 Brownfield Import
Article ID: 451102
Updated On:
Products
Issue/Introduction
- NSX configuration fails on ESXi transport nodes, resulting in the hosts showing a "Failed" state in the NSX UI. The NSX Manager displays the following error:
- Restarting nsx-opsagent/nsx-proxy services on ESXi hosts does not resolve the Failed state in NSX.
- vmkernel.log on the affected ESXi hosts show errors indicating memory exhaustion during module loads:
2026-07-22T20:51:11.373Z -INFO vmkernel - [esx@4413] cpu5:2912925)Loading module nsxt-kcp-25318226 ...
2026-07-22T20:51:11.373Z -WARNING vmkwarning - [esx@4413] cpu5:2912925) Elf: 3728: Kernel based module load of nsxt-kcp-25318226 failed: Out of memory <no mem for Read-Only sections>
...
2026-07-22T20:51:11.434Z -WARNING vmkwarning - [esx@4413] cpu80:2912927) Elf: 3728: Kernel based module load of nsxt-vdl2-25318226 failed: Out of memory <no mem for Read-Only sections>
...
2026-07-22T20:51:11.465Z -WARNING vmkwarning - [esx@4413] cpu109:2912928) Elf: 3728: Kernel based module load of nsxt-vdrb-25318226 failed: Out of memory <no mem for Read-Only sections>
...
2026-07-22T20:51:11.494Z -WARNING vmkwarning - [esx@4413] cpu49:2912929) Elf: 2730: Load of <nsxt-spf-25318226> failed : missing required namespace <com.vmware.nsx.l2#1.1.9.1.25318226>
...
2026-07-22T20:51:11.528Z -WARNING vmkwarning - [esx@4413] cpu70:2912930) Elf: 3728: Kernel based module load of nsxt-vsip-25318226 failed: Out of memory <no mem for Read-Only sections>
...
2026-07-22T20:51:11.557Z -WARNING vmkwarning - [esx@4413] cpu2:2912931) Elf: 3728: Kernel based module load of nsxt-netservice-25318226 failed: Out of memory <no mem for Read-Only sections>
...
2026-07-22T20:51:11.589Z -WARNING vmkwarning - [esx@4413] cpu12:2912932) Elf: 3728: Kernel based module load of nsxt-ens-25318226 failed: Out of memory <no mem for Read-Only sections>Environment
VMware Cloud Foundation 9.x
Cause
The ESXi host is experiencing memory exhaustion (Out of Memory/OOM) causing memory fragmentation. This prevents the allocation of memory for required NSX kernel modules and triggers the termination of the nsx-opsagent service. Without this agent running, the NSX Manager is unable to establish communication to push or verify host configurations, triggering the timeout error.
Resolution
Perform the following workaround on each affected ESXi host:
Place the affected ESXi host in Maintenance Mode within vSphere, and ensure all workloads are fully evacuated.
Reboot the ESXi host to clear the current memory state and alleviate memory pressure.
Wait approximately 10 minutes for the host and its services to fully initialize post-reboot.
Navigate to the NSX UI: System > Fabric > Hosts.
If the NSX Configuration state does not automatically resolve to a healthy state, select the affected host and manually click Configure NSX.
Once the host configuration reaches a "Success" state in NSX, exit Maintenance Mode in vSphere.
Once all ESXi hosts are in a "Success" state in NSX, proceed with restarting the failed import task in VCF.
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