Configuring global firmware management enforces a policy in which all domains within a domain group, or maintenance group (v1.5 and above), run a consistent version of the firmware and hardware capability catalog. Enable a global policy resolution when you want to enforce consistent versions of infrastructure firmware among all domains in a domain group, or maintenance group.
Currently, Cisco UCS Central has two different methods for identifying a domain. Prior to v1.4, the firmware update mechanism was based on the domain group assignment on the domain. Now, the update depends on the tag assigned to the domain. If you tag all of the domains with the same Maintenance Group tag, they are upgraded together. If you tag all of the domains in a domain group, and include all sub-domain groups, they are upgraded together.
When a domain group, or maintenance group, consists of multiple Cisco UCS domains, and you have switched to a global firmware management control policy, be careful of any operational (global) firmware policy changes to that group. Cisco UCS Central tries to upgrade all domains that are members of that domain group, or maintenance group, along with any subdomain groups, as defined in the maintenance policy. The default maintenance policy behavior requires user acknowledgment before any updates occur. You can override this behavior by scheduling an acknowledgment or performing an immediate acknowledgment.