ESXi portgroup missing and here’s the proof

The backup guys came over because a few Avamar Agent backup stopped working for a few Linux virtual machines. Avamar Agent backup uses a dedicated network and hence the VMs have a second interface for the agent. We checked the interface is up with ifconfig eth1 and ethtool eth1 shows it has a link. However, tcpdump -i eth1 detects zero traffic. What are we missing?

The interface for avamar in each VM is connected to portgroup- Backup-Network- which we find is no longer existing. If you look up the VM in vCenter, the portgroup would be greyed out. We ssh to the host and esxcfg-vswitch -l shows there’s no such portgroup. The issue is resolved by creating the portgroup and reconnecting the VM to the portgroup. In vCenter

  • Right click on the VM
  • Edit Settings
  • Click on the Adapter, you will notice the portgroup is blank
  • Choose the portgroup

This step is necessary. Recreating the portgroup alone is not enough for the VM to reconnect to what was existing portgroup. I think this could be due to internal reference VMware uses for a portgroup.

What happened to the portgroup? Well, it was removed. Greping through hostd log, we found this

for i in /scratch/log/hostd.?.gz
zcat $i | grep -C5  Erase

2015-05-20T10:25:52.847Z [594D7B90 verbose 'Hostsvc.NetworkProvider' opID=131DAF7A-0000094A-aa-61] Erase pgName: Backup-Network

Looking a few lines up and down this message, we find the start and stop of the event

2015-05-20T10:25:52.735Z [59741B90 info 'Vimsvc.TaskManager' opID=131DAF7A-0000094A-aa-61] Task Created :
2015-05-20T10:25:52.748Z [594D7B90 verbose 'Hostsvc.NetworkProvider' opID=131DAF7A-0000094A-aa-61] ActionSetVirtualSwitchPortGroup: Updating portgroup
2015-05-20T10:25:52.847Z [594D7B90 verbose 'Hostsvc.NetworkProvider' opID=131DAF7A-0000094A-aa-61] Erase pgName: Backup-Network
2015-05-20T10:25:52.848Z [594D7B90 verbose 'Hostsvc' opID=131DAF7A-0000094A-aa-61] Invoking transaction 161 method updatePortGroup
2015-05-20T10:25:52.848Z [594D7B90 info 'Vimsvc.TaskManager' opID=131DAF7A-0000094A-aa-61] Task Completed : Status success

So who did it? In vCenter

  • Click on the host
  • Task
  • Look for an Update task at the same timestamp (note hostd log is in UTC)
  • You will find your man there

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