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
Solution
How you recover depends on the cause of the degraded cluster state. If the cluster is in a degraded state,
events, alarms, and SNMP traps show errors.
If one of the nodes is down, check for hardware failure or network isolation. Check whether the failed
node is powered on.
In case of replication failures, check if the vCenter HA network has sufficient bandwidth and ensure
network latency is 10 ms or less.
Recovering from Isolated vCenter HA Nodes
If all nodes in a vCenter HA cluster cannot communicate with each other, the Active node stops serving
client requests.
Problem
Node isolation is a network connectivity problem.
Solution
1 Attempt to resolve the connectivity problem. If you can restore connectivity, isolated nodes rejoin the
cluster automatically and the Active node starts serving client requests.
2 If you cannot resolve the connectivity problem, you have to log in to Active node's console directly.
a Power off and delete the Passive node and the Witness node virtual machines.
b Log in to the Active node by using SSH or through the Virtual Machine Console.
c To enable the Bash shell, enter shell at the appliancesh prompt.
d Run the following command to remove the vCenter HA configuration.
destroy-vcha -f
e Reboot the Active node.
The Active node is now a standalone vCenter Server Appliance.
f Perform vCenter HA cluster configuration again.
Resolving Failover Failures
When a Passive node does not become the Active node during a failover, you can force the Passive node
to become the Active node.
Problem
The Passive node fails while trying to assume the role of the Active node.
vSphere Availability
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