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
CPUs that are used in host machines for fault tolerant VMs must be compatible with vSphere vMotion or
improved with Enhanced vMotion Compatibility. Also, CPUs that support Hardware MMU virtualization
(Intel EPT or AMD RVI) are required. The following CPUs are supported.
n
Intel Sandy Bridge or later. Avoton is not supported.
n
AMD Bulldozer or later.
Use a 10-Gbit logging network for FT and verify that the network is low latency. A dedicated FT network is
highly recommended.
Limits
In a cluster congured to use Fault Tolerance, two limits are enforced independently.
das.maxftvmsperhost
The maximum number of fault tolerant VMs allowed on a host in the cluster.
Both Primary VMs and Secondary VMs count toward this limit. The default
value is 4.
das.maxftvcpusperhost
The maximum number of vCPUs aggregated across all fault tolerant VMs on
a host. vCPUs from both Primary VMs and Secondary VMs count toward
this limit. The default value is 8.
Licensing
The number of vCPUs supported by a single fault tolerant VM is limited by the level of licensing that you
have purchased for vSphere. Fault Tolerance is supported as follows:
n
vSphere Standard and Enterprise. Allows up to 2 vCPUs
n
vSphere Enterprise Plus. Allows up to 4 vCPUs
N FT and legacy FT are not supported in vSphere Essentials and vSphere Essentials Plus.
Fault Tolerance Interoperability
vSphere Fault Tolerance faces some limitations concerning the vSphere features, devices, and other features
it can interoperate with.
Before conguring vSphere Fault Tolerance, you must be aware of the features and products Fault Tolerance
cannot interoperate with.
vSphere Features Not Supported with Fault Tolerance
When conguring your cluster, you should be aware that not all vSphere features can interoperate with
Fault Tolerance.
The following vSphere features are not supported for fault tolerant virtual machines.
n
Snapshots. Snapshots must be removed or commied before Fault Tolerance can be enabled on a virtual
machine. In addition, it is not possible to take snapshots of virtual machines on which Fault Tolerance is
enabled.
N Disk-only snapshots created for vStorage APIs - Data Protection (VADP) backups are supported
with Fault Tolerance. However, legacy FT does not support VADP.
n
Storage vMotion. You cannot invoke Storage vMotion for virtual machines with Fault Tolerance turned
on. To migrate the storage, you should temporarily turn o Fault Tolerance, and perform the storage
vMotion action. When this is complete, you can turn Fault Tolerance back on.
Chapter 3 Providing Fault Tolerance for Virtual Machines
VMware, Inc. 43