Decommissioning is performed when a chassis is physically present and connected but you want to temporarily remove it from the Cisco UCS Manager configuration. Because it is expected that a decommissioned chassis will be eventually recommissioned, a portion of the chassis' information is retained by Cisco UCS Manager for future use. Renumbering a Chassis - Before You Begin - If you are swapping IDs between chassis, you must first decommission both chassis, then wait for the chassis decommission FSM to complete before proceeding with the renumbering steps. Reference: https://www.cisco.com/c/en/us/td/docs/unified_computing/ucs/sw/cli/config/guide/3- 0/b_UCSM_CLI_User_Guide_3_0/b_UCSM_CLI_User_Guide_3_0_chapter_0100011.pdf