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
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 conguration les are not properly replicated between the Active and
Passive nodes, the cluster is in a degraded state. The Active node continues
to aempt synchronization with the Passive node. This state can result from
network bandwidth problems or other resource shortages.
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 sucient 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 Aempt to resolve the connectivity problem. If you can restore connectivity, isolated nodes rejoin the
cluster automatically and the Active node starts serving client requests.
Chapter 4 vCenter High Availability
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