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
Troubleshooting a Degraded vCenter HA Cluster
For a vCenter HA cluster to be healthy, each of the Active, Passive, and Witness nodes must be fully
operational and be reachable over the vCenter HA cluster network. If any of the nodes fails, the cluster is
considered to be in a degraded state.
Problem
If the cluster is in a degraded state, failover cannot occur. For information about failure scenarios while
the cluster is in a degraded state, see Resolving Failover Failures.
Cause
The cluster can be in a degraded state for a number of reasons.
One of the nodes fails
n
If the Active node fails, a failover of the Active node to the Passive
node occurs automatically. After the failover, the Passive node
becomes the Active node.
At this point, the cluster is in a degraded state because the original
Active node is unavailable.
After the failed node is repaired or comes online, it becomes the new
Passive node and the cluster returns to a healthy state after the Active
and Passive nodes synchronize.
n
If the Passive node fails, the Active node continues to function, but no
failover is possible and the cluster is in a degraded state.
If the Passive node is repaired or comes online, it automatically rejoins
the cluster and the cluster state is healthy after the Active and Passive
nodes synchronize.
n
If the Witness node fails, the Active node continues to function and
replication between Active and Passive node continues, but no failover
can occur.
If the Witness node is repaired or comes online, it automatically rejoins
the cluster and the cluster state is healthy.
Database replication
fails
If replication fails between the Active and Passive nodes, the cluster is
considered degraded. The Active node continues to synchronize with the
Passive node. If it succeeds, the cluster returns to a healthy state. This
state can result from network bandwidth problems or other resource
shortages.
Configuration file
replication issues
If configuration files are not properly replicated between the Active and
Passive nodes, the cluster is in a degraded state. The Active node
continues to attempt synchronization with the Passive node. This state can
result from network bandwidth problems or other resource shortages.
vSphere Availability
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