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
Virtual Machine Requirements for Fault Tolerance
You must meet the following virtual machine requirements before you use Fault Tolerance.
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No unsupported devices attached to the virtual machine. See Fault Tolerance Interoperability.
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Incompatible features must not be running with the fault tolerant virtual machines. See Fault
Tolerance Interoperability.
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Virtual machine files (except for the VMDK files) must be stored on shared storage. Acceptable
shared storage solutions include Fibre Channel, (hardware and software) iSCSI, vSAN, NFS, and
NAS.
Other Configuration Recommendations
You should also observe the following guidelines when configuring Fault Tolerance.
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If you are using NFS to access shared storage, use dedicated NAS hardware with at least a 1Gbit
NIC to obtain the network performance required for Fault Tolerance to work properly.
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The memory reservation of a fault tolerant virtual machine is set to the VM's memory size when Fault
Tolerance is turned on. Ensure that a resource pool containing fault tolerant VMs has memory
resources above the memory size of the virtual machines. Without this excess in the resource pool,
there might not be any memory available to use as overhead memory.
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To ensure redundancy and maximum Fault Tolerance protection, you should have a minimum of three
hosts in the cluster. In a failover situation, this provides a host that can accommodate the new
Secondary VM that is created.
Configure Networking for Host Machines
On each host that you want to add to a vSphere HA cluster, you must configure two different networking
switches (vMotion and FT logging) so that the host can support vSphere Fault Tolerance.
To set up Fault Tolerance for a host, you must complete this procedure for each port group option
(vMotion and FT logging) to ensure that sufficient bandwidth is available for Fault Tolerance logging.
Select one option, finish this procedure, and repeat the procedure a second time, selecting the other port
group option.
Prerequisites
Multiple gigabit Network Interface Cards (NICs) are required. For each host supporting Fault Tolerance, a
minimum of two physical NICs is recommended. For example, you need one dedicated to Fault Tolerance
logging and one dedicated to vMotion. Use three or more NICs to ensure availability.
Procedure
1 In the vSphere Client, browse to the host.
2 Click the Configure tab and click Networking.
3 Select VMkernel adapters.
vSphere Availability
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