In VirtualCenter Server 2.0.2 and above, you can specify more than one isolation response address for vSphere High Availability (HA). The use of multiple isolation response addresses offers vSphere HA a potentially more accurate picture of the network connectivity of a host. There may be situations in which a single isolation address would indicate that a host is in a state of complete isolation from the network, but access to additional isolation addresses would show that only a partial network failure has occurred.

VMware vCenter Server 6.x
VMware vCenter Server 5.0.x
VMware VirtualCenter 2.0.x
VMware vCenter Server Appliance 6.5.x
VMware vCenter Server 4.1.x
VMware vCenter Server 7.0.x
VMware vCenter Server 5.1.x
VMware vCenter Server 4.0.x
VMware vCenter Server Appliance 6.7.x
VMware vCenter Server 5.5.x

• Set Advanced HA Options
• vSphere HA Advanced Options
• Best Practices for VMware vSphere® High Availability Clusters

In the vSphere Client, browse to the vSphere HA cluster.
    1.  Click the Configure tab.
    2.  Select vSphere Availability and click Edit.
    3.  Click Advanced Options.
    4.  Click Add and type the name of the advanced option in the text box.
            Option: das.isolationaddress0
            Value: A valid IP address other than the default gateway address
            Similarly, you can set more isolation response addresses using das.isolationaddress1 through das.isolationaddress9.

    5.  In the Advanced Options (HA) dialog box, Click Add again and type the name of the advanced option in the text box
            Option: das.usedefaultisolationaddress
            Value: false

         Notes:
            You must set this option if you are setting multiple isolation response addresses.
            Additionally you should configure das.usedefaultisolationaddress to false when the default gateway is a device which cannot be pinged.

    6.  Click OK.
    7.  Edit settings for the cluster again.
    8.  Disable HA and click OK. Wait for the 'Unconfigure vSphere HA' task to complete.
    9.  Edit settings again.
    10. Enable HA and click OK.
    
    Note: If you change the value of any of the following advanced options, you must disable and then re-enable vSphere HA before your changes take effect.

        das.isolationaddress[...]
        das.usedefaultisolationaddress
        das.isolationshutdowntimeout



 

1. Select the HA cluster.
2. On the Summary tab, click Edit Settings.
3. In the Settings dialog, select VMware HA.
4. Click Advanced Options.
5. In the Advanced Options (HA) dialog, enter the option name and the corresponding value:
    
   • Option: das.isolationaddress0
   • Value: A valid IP address other than the default gateway address
     
     Similarly, you can set more isolation response addresses using das.isolationaddress1 through das.isolationaddress9.
      
6. In the Advanced Options (HA) dialog box, set this option:
   • Option: das.usedefaultisolationaddress
   • Value: false
     
     Notes:
     • You must set this option if you are setting multiple isolation response addresses.
     • Additionally you should configure das.usedefaultisolationaddress to false when the default gateway is a device which cannot be pinged.
        
7. Click OK.
8. Click OK.
9. Edit settings for the cluster again.
10. Disable HA and click OK.
11. Edit settings again.
12. Enable HA and click OK.

At the time of VMware HA configuration, if none of the specified addresses can be reached, the configuration operation fails. If only a subset of the specified isolation addresses cannot be reached, then the configuration operation succeeds, but a configuration issue is displayed for the cluster and the cluster becomes yellow. The configuration issue identifies the isolation response addresses that could not be reached.

Although VMware HA supports a maximum of 10 isolation response addresses, in most cases one or two isolation response addresses should be sufficient. Also, the das.isolationaddress option formerly used to set a single isolation response address is still supported.

• Use the default gateway address and other reliable addresses physically close to the hosts in the cluster.
• Ensure a corresponding isolation address is setup for each service console network that has been created on the ESX Server.
• Change the default failure detection time to 20 seconds or greater. To change the default failure detection time:
   
  1. Select the HA cluster.
  2. On the Summary tab, click Edit Settings.
  3. In the Settings dialog, select VMware HA.
  4. Click Advanced Options.
  5. In the Advanced Options (HA) dialog, enter the option name and the corresponding value:
      
     • Option: das.failuredetectiontime
     • Value: A value in milliseconds that represents the timeout value (20 seconds = 20000 milliseconds)
        
  6. Click OK.
  7. Click OK.

Notes:

• das.failuredetectiontime does not need to be increased when multiple das.isolationaddress options are specified as the pings occur in parallel.
• das.failuredetectiontime is no longer supported in vCenter Server 5.0. For more information, see vSphere HA Advanced Attributes.

For information on VMware HA best practices, see Best practices and advanced features for VMware High Availability (1002080).

For further details, see the vSphere Availability guide.

Additional Information

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• 日本語: VMware High Availability の複数の隔離時の応答アドレスの設定 (2076752)
• 简体中文: 为 VMware High Availability 设置多个隔离响应地址 (2077559)