There have been some recent questions about upgrading to the latest version of VMware Tools in vSphere 5.1 and the benefits it may bring with future upgrades of VMware Tools. Historically, VMware Tools upgrades has always required an operating system reboot as new device drivers and kernel modules will not go into effect until the next reboot. For Windows operating systems, you could “suppress” a reboot by specifying an advanced installer option. For UNIX/Linux operating systems, the new device drivers and kernel modules will be staged when you upgrade VMware Tools, but will only be activated upon the next reboot. In both case, you can continue to run your virtual machine in a partially upgraded state for a limited amount of time until your next maintenance window, but it is recommended that you reboot as soon as possible.
In vSphere 5.1, some of you may have heard about something called Zero-down time VMware Tools upgrade where an operating system reboot will no longer be required for upgrading to future versions of VMware Tools. However, this statement is inaccurate and has caused some confusion with our customers. I would like to take this opportunity to help clarify the expected behavior as you plan for VMware Tools upgrade in vSphere 5.1.
Is there downtime when upgrading to vSphere 5.1 version of VMware Tools?
Yes. If you are running VMware Tools prior to vSphere 5.1, an operating system reboot will always be required for new device drivers and kernel modules to go into effect.
Is there downtime when upgrading to future versions of VMware Tools?
It depends. If one or more components have been updated since the last VMware Tools upgrade or one of the VMware Tools components requests a system reboot, then a reboot will be required. The following VMware KB http://kb.vmware.com/kb/2015163 has been created to help identify the components that would require a reboot. A reboot would not be require if only the base components of VMware Tools have been upgraded (e.g. no PVSCSI, VMXNET3). You can refer to the above KB for components that require a reboot.
What has changed in VMware Tools for vSphere 5.1 for upgrades?
We have made improvements in our VMware Tools installer to help reduce the need for operating system reboots when upgrading common components for VMware Tools. This overall reduces the amount of time for managing VMware Tools upgrade as well as reducing or potentially eliminating the amount of downtime required for a system reboot when upgrading VMware Tools.
Which Operating Systems does this apply to?
Windows Vista or greater
What version of virtual hardware or Virtual Machine Compatibility is required?
Virtual Hardware 9 or VMware ESXi 5.1 Compatibility or greater
What about UNIX/Linux Operating Systems?
As mentioned above, this currently only applies to Windows operating system for Vista or greater. However, VMware continues to look for ways to improve the VMware Tools platform and UNIX/Linux operating systems is definitely something that is being looked at.
Is VMware Tools Upgrade Required When Upgrading vSphere?
