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
vSphere makes it possible for organizations to dramatically reduce planned downtime. Because
workloads in a vSphere environment can be dynamically moved to different physical servers without
downtime or service interruption, server maintenance can be performed without requiring application and
service downtime. With vSphere, organizations can:
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Eliminate downtime for common maintenance operations.
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Eliminate planned maintenance windows.
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Perform maintenance at any time without disrupting users and services.
The vSphere vMotion
®
and Storage vMotion functionality in vSphere makes it possible for organizations
to reduce planned downtime because workloads in a VMware environment can be dynamically moved to
different physical servers or to different underlying storage without service interruption. Administrators can
perform faster and completely transparent maintenance operations, without being forced to schedule
inconvenient maintenance windows.
Preventing Unplanned Downtime
While an ESXi host provides a robust platform for running applications, an organization must also protect
itself from unplanned downtime caused from hardware or application failures. vSphere builds important
capabilities into data center infrastructure that can help you prevent unplanned downtime.
These vSphere capabilities are part of virtual infrastructure and are transparent to the operating system
and applications running in virtual machines. These features can be configured and utilized by all the
virtual machines on a physical system, reducing the cost and complexity of providing higher availability.
Key availability capabilities are built into vSphere:
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Shared storage. Eliminate single points of failure by storing virtual machine files on shared storage,
such as Fibre Channel or iSCSI SAN, or NAS. The use of SAN mirroring and replication features can
be used to keep updated copies of virtual disk at disaster recovery sites.
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Network interface teaming. Provide tolerance of individual network card failures.
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Storage multipathing. Tolerate storage path failures.
In addition to these capabilities, the vSphere HA and Fault Tolerance features can minimize or eliminate
unplanned downtime by providing rapid recovery from outages and continuous availability, respectively.
vSphere HA Provides Rapid Recovery from Outages
vSphere HA leverages multiple ESXi hosts configured as a cluster to provide rapid recovery from outages
and cost-effective high availability for applications running in virtual machines.
vSphere HA protects application availability in the following ways:
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It protects against a server failure by restarting the virtual machines on other hosts within the cluster.
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It protects against application failure by continuously monitoring a virtual machine and resetting it in
the event that a failure is detected.
vSphere Availability
VMware, Inc. 7