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
After failures are detected, vSphere HA resets virtual machines. The reset ensures that services remain
available. To avoid reseing virtual machines repeatedly for nontransient errors, by default, virtual
machines will be reset only three times during a certain congurable time interval. After virtual machines
have been reset three times, vSphere HA makes no further aempts to reset the virtual machines after
subsequent failures until after the specied time has elapsed. You can congure the number of resets using
the Maximum per-VM resets custom seing.
N The reset statistics are cleared when a virtual machine is powered o then back on, or when it is
migrated using vMotion to another host. This causes the guest operating system to reboot, but is not the
same as a 'restart' in which the power state of the virtual machine is changed.
VM Component Protection
If VM Component Protection (VMCP) is enabled, vSphere HA can detect datastore accessibility failures and
provide automated recovery for aected virtual machines.
VMCP provides protection against datastore accessibility failures that can aect a virtual machine running
on a host in a vSphere HA cluster. When a datastore accessibility failure occurs, the aected host can no
longer access the storage path for a specic datastore. You can determine the response that vSphere HA will
make to such a failure, ranging from the creation of event alarms to virtual machine restarts on other hosts.
N When you use the VM Component Protection feature, your ESXi hosts must be version 6.0 or higher.
Types of Failure
There are two types of datastore accessibility failure:
PDL
PDL (Permanent Device Loss) is an unrecoverable loss of accessibility that
occurs when a storage device reports the datastore is no longer accessible by
the host. This condition cannot be reverted without powering o virtual
machines.
APD
APD (All Paths Down) represents a transient or unknown accessibility loss
or any other unidentied delay in I/O processing. This type of accessibility
issue is recoverable.
Configuring VMCP
VM Component Protection is congured in the vSphere Web Client. Go to the tab and click
vSphere Availability and Edit. Under Failures and Responses you can select Datastore with PDL or
Datastore with APD. The storage protection levels you can choose and the virtual machine remediation
actions available dier depending on the type of database accessibility failure.
PDL Failures
Under Datastore with PDL, you can select Issue events or Power and
restart VMs.
APD Failures
The response to APD events is more complex and accordingly the
conguration is more ne-grained. You can select Issue events, Power
and restart VMs--conservative restart policy, or Power and restart
VMs--aggressive restart policy
N If either the Host Monitoring or VM Restart Priority seings are disabled, VMCP cannot perform
virtual machine restarts. Storage health can still be monitored and events can be issued, however.
vSphere Availability
16 VMware, Inc.