Upgrading firmware on ESXi hosts
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Upgrading firmware on ESXi hosts


Article ID: 302452


Updated On:


VMware vSphere ESXi


This article provides the best practices for upgrading ESXi firmware.

With ESX classic, in some cases, you may have had agents installed in the Service Console which were used to upgrade the firmware. With ESXi, that approach no longer works due to the absence of a Service Console. Firmware, however, still needs to be upgraded periodically.

Note: Upgrading ESXi firmware is not a service that VMware provides. These methods are not supported by VMware. Contact your hardware vendor on their own best practices where needed.



VMware vSphere ESXi 5.5
VMware vSphere ESXi 5.1
VMware ESXi 4.1.x Installable
VMware ESXi 3.5.x Installable
VMware ESXi 4.1.x Embedded
VMware ESXi 4.0.x Embedded
VMware ESXi 3.5.x Embedded
VMware ESXi 4.0.x Installable
VMware vSphere ESXi 5.0


There are many ways to deal with firmware upgrades for your environment. There is no single approach that works for all environments, as the size of the environment and the type of hardware used dictate which options are available. A decision should be made based on the type of hardware used, the availability of plugins or a centralized solution, and business requirements.

VMware recommends managing the firmware level consistently and following the hardware vendor's recommendations to avoid running into any interdependency issues. When acquiring new hardware, VMware also recommends that you look into the level of integration and the mechanisms that can be leveraged around managing your hardware.

In general, you can upgrade your ESXi firmware using one of three methods:

Hardware vendor bootable CD-ROM/DVD

The first option, bootable CD-ROM/DVD, is the most cumbersome solution but may be the easiest to use. Most hardware vendor have free ISOs available for download that contain the latest firmware version(s). These are usually categorized by server model and can be used to boot a host. This is, however, a manual task and is most likely something that might be easiest in environments with less than 15 hosts.

Hardware vendor vCenter Server Plugin or management application

Some hardware vendors provide management plugins that can be used for upgrading the firmware. This option is worth investigating. Some vendors even offer plugins for vCenter Server, which may be able to upgrade firmware.

Some vendors also have a centralized management application to manage their hardware end-to-end, which includes the capabilities to upgrade firmware. These solutions offer a single point of interface for your hardware, enabling you to manage several layers at once

PXE Boot of small Linux distribution/vendors upgrade CD/DVD

Some vendors use a tiny linux distribution (such as JeOS) and PXE boot the server with that distribution. This distribution contains the latest versions of the firmware, or it connects to a central repository and automatically updates the server. Especially in very large environments, a solution like this can be used as a uniform mechanism to deploy new versions of firmware across multiple hardware vendors. This would be possible as well if you develop your own tool.

Upgrading ESXi 5.x firmware

VMware provides a framework for updating firmware via CIM. Usually, partners implement the Software Update Profile with their CIM provider. This profile enables providers to update firmware on the host, fetching the firmware image either from an http/https location or by having the firmware image pushed to the CIM provider via an xml transport. The CIM software update profile is an industry standard. For more information, see http://www.dmtf.org/sites/default/files/standards/documents/DSP1025_1.0.0.pdf.

As a practical matter, this means that you would control or initiate a firmware update using a partner's CIM client, not via VMware software.

Firmware itself can be packaged as a VIB. ESXi does not have permanent storage available in the filesystem from programs. If there is a need to install something permanently, it must be packaged as a VIB, and then installation of the VIB is invoked from the CIM provider. In other words, the VIB installation stores whatever it is packaged in the VIB and makes it available in the filesystem (immediately if it is a live-install VIB, or on the next reboot if it is not).

Note: Remote installation of a driver via CIM is not supported. Driver installation is done via ESXCLI or VUM.