6.0.1

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.
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It protects against datastore accessibility failures by restarting affected virtual machines on other hosts
which still have access to their datastores.
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It protects virtual machines against network isolation by restarting them if their host becomes isolated
on the management or Virtual SAN network. This protection is provided even if the network has
become partitioned.
Unlike other clustering solutions, vSphere HA provides the infrastructure to protect all workloads with the
infrastructure:
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You do not need to install special software within the application or virtual machine. All workloads are
protected by vSphere HA. After vSphere HA is configured, no actions are required to protect new
virtual machines. They are automatically protected.
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You can combine vSphere HA with vSphere Distributed Resource Scheduler (DRS) to protect against
failures and to provide load balancing across the hosts within a cluster.
vSphere Availability
10 VMware, Inc.