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
After these checks are passed, the Primary and Secondary VMs are powered on and placed on
separate, compatible hosts. The virtual machine's Fault Tolerance Status is tagged as Protected.
Turn On Fault Tolerance
You can turn on vSphere Fault Tolerance through the vSphere Client.
When Fault Tolerance is turned on, vCenter Server resets the virtual machine's memory limit and sets the
memory reservation to the memory size of the virtual machine. While Fault Tolerance remains turned on,
you cannot change the memory reservation, size, limit, number of vCPUs, or shares. You also cannot add
or remove disks for the VM. When Fault Tolerance is turned off, any parameters that were changed are
not reverted to their original values.
Connect vSphere Client to vCenter Server using an account with cluster administrator permissions.
Prerequisites
The option to turn on Fault Tolerance is unavailable (dimmed) if any of these conditions apply:
n
The virtual machine resides on a host that does not have a license for the feature.
n
The virtual machine resides on a host that is in maintenance mode or standby mode.
n
The virtual machine is disconnected or orphaned (its .vmx file cannot be accessed).
n
The user does not have permission to turn the feature on.
Procedure
1 In the vSphere Client, browse to the virtual machine for which you want to turn on Fault Tolerance.
2 Right-click the virtual machine and select Fault Tolerance > Turn On Fault Tolerance.
3 Click Yes.
4 Select a datastore on which to place the Secondary VM configuration files. Then click Next.
5 Select a host on which to place the Secondary VM. Then click Next.
6 Review your selections and then click Finish.
The specified virtual machine is designated as a Primary VM, and a Secondary VM is established on
another host. The Primary VM is now fault tolerant.
Note The VM datastores and memory are replicated during the FT Turn On process. This can take
several minutes depending on the size of the replicated data. The VM state does not appear as protected
until replication is complete.
Turn O Fault Tolerance
Turning off vSphere Fault Tolerance deletes the secondary virtual machine, its configuration, and all
history.
vSphere Availability
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