Migrating an ESXi/ESX host from one vCenter Server to another without disconnecting may cause statistics collection to fail

Products

• VMware vCenter Server
• VMware vSphere ESXi

Issue/Introduction

Symptoms:

• Performance data is missing in vCenter Server.
  
• Performance charts display the error:
  
  no data available
  
  
• DRS is unable to make a calculation causing virtual machines not to migrate during heavy load on the ESXi/ESX host.
• You see error messages in the vpxa log similar to:
  
  2012-05-04T23:44:38.279Z [3BC13B90 warning 'hostdstats'] [FetchQuickStats] GetTranslators -- host to vpxd translation is empty. Dropping results
2012-05-04T23:44:38.279Z [3BC13B90 warning 'vpxavpxaAlarm'] [AddEntityMetric] GetTranslators -- host to vpxd translation is empty. Dropping results

Environment

VMware vCenter Server 5.0.x
VMware vCenter Server 4.0.x
VMware vCenter Server 4.1.x
VMware vSphere ESXi 5.1
VMware vCenter Server 5.1.x

Cause

This issue is caused when removing an ESXi/ESX server from one vCenter Server and then adding it to a new vCenter Server without disconnecting it from the original. This can cause the vpxa agent on the host to not provide stats to the new vCenter Server (that is, performance statistics collection fails).

This can lead to:

• Performance charts failing to function:
  
  
  • After the migration, performance charts in vCenter Server may fail to collect data
  • Performance charts may report no data available errors
  
  
• DRS can cause a vCenter Server imbalance which in turn causes high levels of contention on the ESXi/ESX host. Without performance statistics, DRS treats the virtual machines as 100 percent active, and proceeds to migrate the virtual machines to new ESXi/ESX hosts.

Resolution

This is a known issue affecting vCenter Server 4.0.x, 4.1.x, 5.0, and 5.1.

This issue is resolved in vCenter Server 5.5. You can download the latest vCenter Server release from the VMware Download Center.

To work around this issue when you do not want to upgrade, disconnect and then reconnect the ESXi/ESX host in the current vCenter Server inventory:

1. Log in to vCenter Server with the vSphere Client.
2. Click Home > Hosts and Clusters.
3. Right-click the ESXi/ESX host, then click Disconnect. Wait for the task to complete.
   
4. Right-click the ESXi/ESX host, then click Reconnect.
   
   Note: You may be prompted to provide a username and password to reconnect the host.

Additional Information

ESXi/ESXホストをあるvCenter Serverから別のvCenter Serverへ切断なしで移行した場合に統計情報の収集に失敗する