6.5.1
Table Of Contents
- vSphere Availability
- Contents
- About vSphere Availability
- Business Continuity and Minimizing Downtime
- Creating and Using vSphere HA Clusters
- Providing Fault Tolerance for Virtual Machines
- vCenter High Availability
- Plan the vCenter HA Deployment
- Configure the Network
- Configure vCenter HA With the Basic Option
- Configure vCenter HA With the Advanced Option
- Manage the vCenter HA Configuration
- Set Up SNMP Traps
- Set Up Your Environment to Use Custom Certificates
- Manage vCenter HA SSH Keys
- Initiate a vCenter HA Failover
- Edit the vCenter HA Cluster Configuration
- Perform Backup and Restore Operations
- Remove a vCenter HA Configuration
- Reboot All vCenter HA Nodes
- Change the Appliance Environment
- Collecting Support Bundles for a vCenter HA Node
- Troubleshoot Your vCenter HA Environment
- Patching a vCenter High Availability Environment
- Using Microsoft Clustering Service for vCenter Server on Windows High Availability
- Index
Configure Admission Control
After you create a cluster, you can congure admission control to specify whether virtual machines can be
started if they violate availability constraints. The cluster reserves resources so that failover can occur for all
running virtual machines on the specied number of hosts.
The Admission Control page appears only if you enabled vSphere HA.
Procedure
1 In the vSphere Web Client, browse to the vSphere HA cluster.
2 Click the tab.
3 Select vSphere Availability and click Edit.
4 Click Admission Control to display the conguration options.
5 Select a number for the Host failures cluster tolerates. This is the maximum number of host failures
that the cluster can recover from or guarantees failover for.
6 Select an option for host failover capacity by.
Option Description
Cluster resource percentage
Specify a percentage of the cluster’s CPU and memory resources to reserve
as spare capacity to support failovers.
Slot Policy (powered-on VMs)
Select a slot size policy that covers all powered on VMs or is a xed size.
You can also calculate how many VMs require multiple slots.
Dedicated failover hosts
Select hosts to use for failover actions. Failovers can still occur on other
hosts in the cluster if a default failover host does not have enough
resources.
Disabled
Select this option to disable admission control and allow virtual machine
power ons that violate availability constraints.
7 Set the percentage for the Performance degradation VMs tolerate.
This seing determines what percentage of performance degradation the VMs in the cluster are allowed
to tolerate during a failure.
8 Click OK.
Your admission control seings take eect.
Configure Heartbeat Datastores
vSphere HA uses datastore heartbeating to distinguish between hosts that have failed and hosts that reside
on a network partition. With datastore heartbeating, vSphere HA can monitor hosts when a management
network partition occurs and continue to respond to failures.
You can specify the datastores that you want to be used for datastore heartbeating.
Procedure
1 In the vSphere Web Client, browse to the vSphere HA cluster.
2 Click the tab.
3 Select vSphere Availability and click Edit.
4 Click Heartbeat Datastores to display the conguration options for datastore heartbeating.
Chapter 2 Creating and Using vSphere HA Clusters
VMware, Inc. 33