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
Table 4‑1. vCenter HA Nodes
Node Description
Active
n
Runs the active vCenter Server Appliance instance
n
Uses a public IP address for the management interface
n
Uses the vCenter HA network for replication of data to the Passive node.
n
Uses the vCenter HA network to communicate with the Witness node.
Passive
n
Is initially a clone of the Active node
n
Constantly receives updates from and synchronizes state with the Active node over the vCenter HA network
n
Automatically takes over the role of the Active node if a failure occurs
Witness
n
Is a lightweight clone of the Active node
n
Provides a quorum to protect against a split-brain situations
vCenter HA Hardware and Software Requirements
Before you set up vCenter HA, ensure that you have sufficient memory, CPU, and datastore resources,
and ensure that you are using versions of vCenter Server and ESXi that support vCenter HA.
Your environment must meet the following requirements.
Table 4‑2. vCenter HA Requirements
Component Requirements
ESXi
n
ESXi 5.5 or later is required.
n
Three hosts are strongly recommended. Each vCenter HA node can then run on a
different host for better protection.
n
Using VMware DRS to protect the set of hosts is recommended. In that case, a
minimum of three ESXi hosts is required.
Management vCenter Server (if used) Your environment can include a management vCenter Server system, or you can set
up your vCenter Server Appliance to manage the ESXi host on which it runs (self-
managed vCenter Server)
n
vCenter Server 5.5 or later is required.
vCenter Server Appliance
n
vCenter Server 6.5 is required.
n
Deployment size Small (4 CPU and 16GB RAM) or bigger is required to meet the
RTO. Do not use Tiny in production environments.
n
vCenter HA is supported and tested with VMFS, NFS, and vSAN datastores.
n
Ensure you have enough disk space to collect and store support bundles for all
three nodes on the Active node. See Collecting Support Bundles for a vCenter HA
Node.
Network connectivity
n
vCenter HA network latency between Active, Passive, and Witness nodes must be
less than 10 ms.
n
The vCenter HA network must be on a different subnet than the management
network.
Licensing required for vCenter HA
n
vCenter HA requires a single vCenter Server license.
n
vCenter HA requires a Standard license.
vSphere Availability
VMware, Inc. 71