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
Manage vCenter HA SSH Keys
vCenter HA uses SSH keys for password-less authentication between the Active, Passive, and Witness
nodes. The authentication is used for heartbeat exchange and file and data replication. To replace the
SSH keys in the nodes of a vCenter HA cluster, you disable the cluster, generate new SSH keys on the
Active node, transfer the keys to the passive node, and enable the cluster.
Procedure
1 Edit the cluster and change the mode to Disabled.
2 Log in to the Active node by using the Virtual Machine Console or SSH.
3 Enable the bash shell.
bash
4 Run the following command to generate new SSH keys on the Active node.
/usr/lib/vmware-vcha/scripts/resetSshKeys.py
5 Use SCP to copy the keys to the Passive node and Witness node.
scp /vcha/.ssh/*
6 Edit the cluster configuration and set the vCenter HA cluster to Enabled.
Initiate a vCenter HA Failover
You can manually initiate a failover and have the Passive node become the Active node.
A vCenter HA cluster supports two types of failover.
Automatic failover The Passive node attempts to take over the active role in case of an Active
node failure.
Manual failover The user can force a Passive node to take over the active role by using the
Initiate Failover action.
Initiate a manual failover for troubleshooting and testing.
Procedure
1 Log in to the Active node vCenter Server Appliance with the vSphere Web Client and click
Configure.
2 Under Settings select vCenter HA and click Initiate Failover.
3 Click Yes to start the failover.
A dialog offers you the option to force a failover without synchronization. In most cases, performing
synchronization first is best.
vSphere Availability
VMware, Inc. 84