An EPLD update of the supervisor module of fabric switches (Cisco MDS 9100, Cisco MDS 9200, and Cisco MDS 9300 Series switches) is disruptive since there is no redundant supervisor to take over while the update is in progress. All traffic through the system is stopped for the duration of the update and the switch is rebooted after the upgrade has completed. The update may take up to 30 minutes to complete. https://www.cisco.com/c/en/us/td/docs/switches/datacenter/mds9000/sw/6_2/release/notes/epld/epld_rn.html#pg