Change HA Settings

Once HA has been enabled on a pool, you can change VM startup settings and adjust the server failure limit for the pool from the Configure HA dialog box.

To change HA restart priority and VM startup sequence settings

1. Select the pool in the Resources pane, click on the HA tab, and then click Configure HA. Alternatively:
   • On the Pool menu, click High Availability.
   • Right-click in the Resources pane and then click High Availability on the shortcut menu.

2. Select one or more VMs in the list and set the required VM startup settings. For more on these options, see VM startup settings. To select more than one virtual machine, click at the start of the selection, scroll to the end of the selection, and then hold down SHIFT while you click where you want the selection to end. To select several virtual machines that are not next to each other in the list, click the first one, press CTRL, and then click the additional virtual machines that you want to select.

   Set the following options:

   • HA restart priority : Choose a restart priority for each VM:
     • Choose Restart to ensure the selected VM(s) are restarted if sufficient resources are available within the pool.
     • Choose Restart if Possible if it is not essential to restart the VM automatically.
     • Choose Do Not Restart if you never want the VM to be restarted automatically.
   • Start order : Specifies the order in which individual VMs will be started up during the HA recovery operation, allowing certain VMs to be started before others. VMs with a start order value of 0 (zero) will be started first, then VMs with a start order value of 1, followed by VMs with a start order value of 2, and so on.
   • Attempt to start next VM after : This is a delay interval that specifies how long to wait after starting the VM before attempting to start the next group of VMs in the startup sequence, that is, VMs with a lower start order.
3. Click OK to apply the changes and close the dialog box.

To change the server failure limit for a pool

1. Select the pool in the Resources pane, click on the HA tab, and then click Configure HA. Alternatively:
   • On the Pool menu, click High Availability.
   • Right-click in the Resources pane and then click High Availability on the shortcut menu.
2. Under Server failure limit , enter the number of server failures to allow. This value should be less than or equal to the maximum failure capacity for the pool, shown here as max . If max is 0 (zero), the pool is overcommitted, and you will not be able to save the change without either adjusting the HA restart priorities or making more resources available within the pool; see To increase the maximum failure capacity for a pool.
3. Click OK to apply the changes and close the dialog box.

To increase the maximum failure capacity for a pool

To increase the maximum failure capacity for a pool, you need to do one or more of the following:

• Reduce the HA restart priority of some VMs.
• Increase the amount of RAM on your servers or add more servers to the pool to increase its capacity.
• Reduce the amount of memory configured on some VMs.
• Shut down non-essential VMs.