Some vNICs are disconnected after restoring NSX Manager

Products

• VMware NSX

Issue/Introduction

• You have restored NSX Manager to backup.
  • You registered Compute Manager on newly deployed NSX Manager before starting restore.

• Before restore completed or after a while, some vNICs went disconnected and communication fails.
  • The ports are not recognized in vSphere Client.
  • Inside the guest OS, the NIC looks link down.

• You see sync-detach requests sent to NSX Manager for some vNICs.
  nsx-syslog
  <Timestamp> In(182) nsx-opsagent[<NNNNNN>]: NSX <NNNNNN> - [nsx@6876 comp="nsx-esx" subcomp="opsagent" s2comp="nsxa" tid="<NNNNNN>" level="INFO"] [DoVifPortOperation] request=[opId:[sync-detach-0] op:[SYNC_DETACH_PORT(1002)] vif:[<UUID>] ls:[<UUID>] vmx:[/vmfs/volumes/<Datastore>/<VM directory>/<VMX filename>.vmx] lp:[<UUID>]]

 

Environment

VMware NSX

Cause

DO NOT register any Compute Manager during restore steps.
Compute Manager registration is contained in your backup and restored along with other configurations.

When NSX Manager gets connected to vCenter, it compares NSX portgroups on VC with its NSX segment, and adds or deletes NSX porgroups on VC to keep NSX segments synced.
As a fresh NSX Manager has no NSX segments before restoration, it deletes all the NSX portgroups on VC if you register the VC on NSX Manager.

NSX portgroups are created again during restore, but NSX ports on ESXi might get detached by periodic resync.
It cleans up ports that do not belong to a portgroup.

nsxaVim.log
<Timestamp> Db(15) nsxaVim: [221882757]: DEBUG [resync] VM Vnic port <UUID> does not belong to a LSPG or security DVPG 
...
<Timestamp> In(14) nsxaVim: [221882757]: INFO [resync] resync doing VM crosscheck
...
<Timestamp> In(14) nsxaVim: [221882757]: INFO [resync] port2delete=[[]] port2detach=[[<List of port UUIDs to be detached>]] vnic2attach=[[]]

Resolution

DO NOT register any compute manager during restore steps.

If you have done it, connect the affected vNICs to another potgroup and then connect them back to the original NSX portgroup.

Additional Information

Read the document and carefully follow the steps when you restore a backup.

Restore a Backup

The document does not suggest you register Compute Manager during the steps.