6.7
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
- How Fault Tolerance Works
- Fault Tolerance Use Cases
- Fault Tolerance Requirements, Limits, and Licensing
- Fault Tolerance Interoperability
- Preparing Your Cluster and Hosts for Fault Tolerance
- Using Fault Tolerance
- Best Practices for Fault Tolerance
- Legacy Fault Tolerance
- Troubleshooting Fault Tolerant Virtual Machines
- Hardware Virtualization Not Enabled
- Compatible Hosts Not Available for Secondary VM
- Secondary VM on Overcommitted Host Degrades Performance of Primary VM
- Increased Network Latency Observed in FT Virtual Machines
- Some Hosts Are Overloaded with FT Virtual Machines
- Losing Access to FT Metadata Datastore
- Turning On vSphere FT for Powered-On VM Fails
- FT Virtual Machines not Placed or Evacuated by vSphere DRS
- Fault Tolerant Virtual Machine Failovers
- 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
6 Select an option for Define 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 fixed 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 setting determines what percentage of performance degradation the VMs in the cluster are
allowed to tolerate during a failure.
8 Click OK.
Your admission control settings take effect.
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 Client, browse to the vSphere HA cluster.
2 Click the Configure tab.
3 Select vSphere Availability and click Edit.
4 Click Heartbeat Datastores to display the configuration options for datastore heartbeating.
5 To instruct vSphere HA about how to select the datastores and how to treat your preferences, select
from the following options.
Table 2‑3.
Datastore Heartbeating Options
Automatically select datastores accessible from the host
Use datastores only from the specified list
Use datastores from the specified list and complement automatically if needed
vSphere Availability
VMware, Inc. 39