As mentioned on Scott Lowe and Duncan Epping’s sites, an issue has been uncovered with VMware ESX 3.5 Update 3 in regards to Virtual Machines rebooting when using VMware HA with Virtual Machine Monitoring enabled.

To stay up to date on this VMware KB, please visit their website; VMware KB 1007899

**Symptoms:

** Virtual Machines may unexpectedly reboot after a VMotion migration to an ESX 3.5 Update 3 Host OR after a Power On operation on an ESX 3.5 Update 3 Host, when VMware HA feature with Virtual Machine Monitoring is active.

**Purpose:

** A virtual machine may reboot itself when the following conditions exist:

• Virtual Machine is running on ESX 3.5 Update 3 Host, either by virtue of VMotion or a Power On operation, and

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• Host has VMware HA enabled with “Virtual Machine Monitoring” option active.

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  Virtual Machine monitoring is dependent on VMware tools heartbeats to determine the state of the Virtual Machines.

  With ESX Server 3.5 Update 3 after a VMotion or Power On operation, host agent running on the ESX server may delay sending the heartbeat state of the Virtual Machine to the Host. VMware HA detects this as a failure of the Virtual Machine and attempts to restart the Virtual Machine

  Resolution:
  To work around this problem:

  Option 1: Disable Virtual Machine Monitoring
  1. Select the VMware HA cluster and choose Edit Settings from the right-click menu (note that this feature can also be enabled for a new cluster on the VMware HA page of the New Cluster wizard).
  2. In the Cluster Settings dialog box, select VMware HA in the left column.
  3. Un-Check the Enable virtual machine monitoring check box.
  4. Click OK.
  Option 2: Set hostd hearbeat delay to 0
  1. Disconnect the host from VC (Right click on host in VI Client and select “Disconnect” )
  2. Login as root to the ESX Server with SSH.
  3. Using a text editor such as nano or vi, edit the file /etc/vmware/hostd/config.xml
  4. Set the “heartbeatDelayInSecs” tag under “vmsvc” to 0 seconds as shown here:
     
     0
     true
     
  5. Restart the management agents for this change to take effect.  See Restarting the Management agents on an ESX Server
  6. Reconnect the host in VC ( Right click on host in VI Client and select “Connect” )</p>

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