When you upgrade virtual machines, the required downtime depends on the guest operating system and the type of upgrade you are performing.

When you upgrade VMware Tools, expect the following downtime:

No downtime is required for vCenter Server.

No downtime is required for ESXi hosts.

For Windows guest operating systems, you must restart the virtual machines at the end of the upgrade procedure, or later, for the upgrade take effect. You must always restart the virtual machine after you upgrade VMware Tools and after you upgrade the virtual machine compatibility.

For Linux guest operating systems, you must restart the virtual machine to load the new versions of the VMXNET, VMXNET3, and PVSCSI drivers. You can also manually reload the drivers. To verify that the drivers are configured in the Linux kernel and that the virtual hardware is available, see Knowledge Base article, http://kb.vmware.com/kb/2050364. Note that manual restart is not required for the Linux guest operating system using kernel version 3.10.

For BSD, NetWare, Solaris, and Mac OS X guest operating systems, no restart is required at the end of the procedure.

During the virtual machine compatibility upgrade, you must shut down the virtual machine for all guest operating systems.

Virtual Machine Downtime by Guest Operating System

Guest Operating System

Upgrade VMware Tools

Upgrade Virtual Machine Compatibility

Microsoft Windows

Downtime to restart the guest operating system.

Downtime to shut down and power on the virtual machine.

Linux

Downtime to restart the guest operating system is required to load drivers.

Downtime to shut down and power on the virtual machine.

NetWare

No downtime.

Downtime to shut down and power on the virtual machine.

Solaris

No downtime.

Downtime to shut down and power on the virtual machine.

FreeBSD

No downtime.

Downtime to shut down and power on the virtual machine.

Mac OS X

No downtime.

Downtime to shut down and power on the virtual machine.