Precheck fails while migrating NSX-T NVDS to VDS

Products

• VMware NSX Networking

Issue/Introduction

Symptoms:

• You are running NSX-T version less than 3.2.2.
• You are migrating the host switch from NVDS (NSX VDS) to CVDS (vCenter VDS).
• The host that fails the precheck is a standalone host and is not part of a vCenter cluster.
• Migration of switch fails with precheck status failed.
• In the NSX manager log /var/log/proton/nsxapi.log you will see the the following error:

2022-09-01T15:59:48.261Z INFO http-nio-127.0.0.1-7440-exec-48 NvdsUpgradeReadinessCheckServiceImpl 10919 FABRIC [nsx@6876 comp="nsx-manager" level="INFO" reqId="1d6b3dc9-b266-47c3-9669-3f075dd2ea44" subcomp="manager" username="admin"] NVDS-UPGRADE triggerNvdsUpgradePrecheck precheckStatus FAILED
...
2022-09-01T15:59:48.261Z INFO NvdsUpgradeTaskExecutor1 NvdsUpgradeReadinessCheckServiceImpl 18480 FABRIC [nsx@6876 comp="nsx-manager" level="INFO" subcomp="manager"] NVDS-UPGRADE exception in validateNvdsUpgradeConfig: java.lang.NullPointerException

• As admin on the NSX-T manager, when you run the following pre check, it fails:

NSX-mgr01> vds-migrate precheck

GetVDSUpgradeSummary: {"precheck_id": "a2fa9275-d459-473a-b509-557eacfaa3da", "precheck_status": "FAILED"}

Environment

VMware NSX-T Data Center
VMware NSX-T Data Center 3.x

Cause

This issue occurs if the host is not part of any vCenter cluster and is a standalone host. Standalone hosts have a null payload in the internal DB and NSX-T incorrectly tries to process this entry, which results in the NPE (Null Pointer Exception).

Resolution

This issue is resolved in NSX-T version 3.2.2, whereby NSX-T will correctly handle the null entry for the host. The host still needs to be part of a cluster in vCenter to be migrated.

Workaround:
Ensure all transport nodes are under a vCenter cluster prior migration of NVDS to VDS.