Specifications

Overview of the Upgrade Process 1
Upgrading is a multistage process in which procedures must be performed in a particular order. Follow the
process outlined in this high-level overview to ensure a smooth upgrade with a minimum of system
downtime.
IMPORTANT Make sure that you understand the entire upgrade process before you attempt to upgrade. If
you do not follow the safeguards, you might lose data and access to your servers. Without planning, you
might incur more downtime than is necessary.
If you use vCenter Server Heartbeat in your vSphere deployment, use the vSphere Server Heartbeat
installation and upgrade documentation to upgrade vCenter Server.
vCenter Server 5.5 removes support for Windows Server 2003 as a host operating system. See the VMware
Compatibility Guide at http://www.vmware.com/resources/compatibility/search.php and “Migrate vCenter
Server and Components from a Windows Server 2003 Host,” on page 109.
vCenter Server 5.5 removes support for Windows Server 2008 SP1 as a host operating system. Upgrade
Windows Server 2008 SP1 hosts to SP2 before upgrading vCenter Server to version 5.5. See the VMware
Compatibility Guide at http://www.vmware.com/resources/compatibility/search.php and the Microsoft
Software Lifecycle Policy at http://support.microsoft.com/lifecycle/#ServicePackSupport.
You must complete the upgrade process in a specific order because you can lose data and server access.
Order is also important within each upgrade stage.
You can perform the upgrade process for each component in only one direction. For example, after you
upgrade to vCenter Server 5.x, you cannot revert to vCenter Server 4.x. With backups and planning, you can
restore your original software records.
You must complete one procedure before you move to the next procedure. Follow the directions within each
procedure regarding the required sequence of minor substeps.
Because certain commands can simultaneously upgrade more than one stage, VMware recommends that
you understand the irreversible changes at each stage before you upgrade your production environments.
To ensure that your datacenter upgrade goes smoothly, you can use vCenter Update Manager to manage
the process for you.
vSphere upgrades proceed in the following sequence of tasks.
1 If your vSphere system includes VMware solutions or plug-ins, make sure they are compatible with the
vCenter Server version that you are upgrading to. See the VMware Product Interoperability Matrix at
http://www.vmware.com/resources/compatibility/sim/interop_matrix.php.
2 If you are upgrading vSphere components that are part of a VMware View environment, see
“Upgrading vSphere Components Separately in a Horizon View Environment,” on page 220.
VMware, Inc.
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