The most recent UCSM firmware version available at the time of writing this book is UCSM 3.1. Always check the Cisco website to acquire the most recent firmware. It is necessary to have a CCO account and authorization in order to download the UCSM firmware. Older firmware versions are also available in the archive area of the same web page.

The following are the major firmware releases:

• UCSM version 1.4
• UCSM version 2.2
• UCSM version 3.0 (UCS Mini only)
• UCSM version 3.1

For each major release, there are some minor revisions as well. When performing a firmware upgrade, always read the firmware release notes carefully in order to avoid breaking a production environment. For example, if you have configured default SAN zoning (not recommended, but configurable in version 2.0) for production systems running on firmware version 2.0, upgrading to firmware version 2.1 will break the SAN access unless proper zoning is configured, as default zoning is not an option in version 2.1.