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
Configuring VMCP
VM Component Protection is configured in the vSphere Client. Go to the Configure tab and click
vSphere Availability and Edit. Under Failures and Responses you can select Datastore with PDL or
Datastore with APD. The storage protection levels you can choose and the virtual machine remediation
actions available differ depending on the type of database accessibility failure.
PDL Failures Under Datastore with PDL, you can select Issue events or Power off and
restart VMs.
APD Failures
The response to APD events is more complex and accordingly the
configuration is more fine-grained. You can select Issue events, Power off
and restart VMs--conservative restart policy, or Power off and restart
VMs--aggressive restart policy
Note If either the Host Monitoring or VM Restart Priority settings are disabled, VMCP cannot perform
virtual machine restarts. Storage health can still be monitored and events can be issued, however.
Network Partitions
When a management network failure occurs for a vSphere HA cluster, a subset of the cluster's hosts
might be unable to communicate over the management network with the other hosts. Multiple partitions
can occur in a cluster.
A partitioned cluster leads to degraded virtual machine protection and cluster management functionality.
Correct the partitioned cluster as soon as possible.
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Virtual machine protection. vCenter Server allows a virtual machine to be powered on, but it can be
protected only if it is running in the same partition as the master host that is responsible for it. The
master host must be communicating with vCenter Server. A master host is responsible for a virtual
machine if it has exclusively locked a system-defined file on the datastore that contains the virtual
machine's configuration file.
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Cluster management. vCenter Server can communicate with the master host, but only a subset of the
slave hosts. As a result, changes in configuration that affect vSphere HA might not take effect until
after the partition is resolved. This failure could result in one of the partitions operating under the old
configuration, while another uses the new settings.
Datastore Heartbeating
When the master host in a VMware vSphere
®
High Availability cluster cannot communicate with a
subordinate host over the management network, the master host uses datastore heartbeating to
determine whether the subordinate host has failed, is in a network partition, or is network isolated. If the
subordinate host has stopped datastore heartbeating, it is considered to have failed and its virtual
machines are restarted elsewhere.
vSphere Availability
VMware, Inc. 18