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
Using Fault Tolerance with DRS
You can use vSphere Fault Tolerance with vSphere Distributed Resource Scheduler (DRS) only when the
Enhanced vMotion Compatibility (EVC) feature is enabled. This process allows fault tolerant virtual
machines to benet from beer initial placement.
When a cluster has EVC enabled, DRS makes the initial placement recommendations for fault tolerant
virtual machines and allows you to assign a DRS automation level to Primary VMs (the Secondary VM
always assumes the same seing as its associated Primary VM.)
When vSphere Fault Tolerance is used for virtual machines in a cluster that has EVC disabled, the fault
tolerant virtual machines are given DRS automation levels of "disabled". In such a cluster, each Primary VM
is powered on only on its registered host and its Secondary VM is automatically placed.
If you use anity rules with a pair of fault tolerant virtual machines, a VM-VM anity rule applies to the
Primary VM only, while a VM-Host anity rule applies to both the Primary VM and its Secondary VM. If a
VM-VM anity rule is set for a Primary VM, DRS aempts to correct any violations that occur after a
failover (that is, after the Primary VM eectively moves to a new host).
Preparing Your Cluster and Hosts for Fault Tolerance
To enable vSphere Fault Tolerance for your cluster, you must meet the feature's prerequisites and you must
perform certain conguration steps on your hosts. After those steps are accomplished and your cluster has
been created, you can also check that your conguration complies with the requirements for enabling Fault
Tolerance.
The tasks you should complete before aempting to set up Fault Tolerance for your cluster include the
following:
n
Ensure that your cluster, hosts, and virtual machines meet the requirements outlined in the Fault
Tolerance checklist.
n
Congure networking for each host.
n
Create the vSphere HA cluster, add hosts, and check compliance.
After your cluster and hosts are prepared for Fault Tolerance, you are ready to turn on Fault Tolerance for
your virtual machines. See “Turn On Fault Tolerance,” on page 49.
Fault Tolerance Checklist
The following checklist contains cluster, host, and virtual machine requirements that you need to be aware
of before using vSphere Fault Tolerance.
Review this list before seing up Fault Tolerance.
N The failover of fault tolerant virtual machines is independent of vCenter Server, but you must use
vCenter Server to set up your Fault Tolerance clusters.
Cluster Requirements for Fault Tolerance
You must meet the following cluster requirements before you use Fault Tolerance.
n
Fault Tolerance logging and VMotion networking congured. See “Congure Networking for Host
Machines,” on page 46.
n
vSphere HA cluster created and enabled. See “Creating a vSphere HA Cluster,” on page 27. vSphere
HA must be enabled before you can power on fault tolerant virtual machines or add a host to a cluster
that already supports fault tolerant virtual machines.
Chapter 3 Providing Fault Tolerance for Virtual Machines
VMware, Inc. 45