Hello UKC_SD,   You can update the CMC without downtime. When the CMC reboots everything in the chassis will still continue to run. However the main board caution:  The chassis infrastructure update operation updates the Main Board component. NOTE: Before you update the Chassis Infrastructure firmware, turn off all the servers in the chassis if required. I would plan a maintenance window when you can shut everything down.   The FC640 iDRACs would need to be brought to 3.30.30.30 then update to current.  The rest can be updated to current with the bootable ISO.   Reference information:  Updating firmware pages 39-51 : [URL]   For the OS update, I'd recommend to use DellEMC Customized Image of VMware ESXi 7.0 U2 it has our validated drivers included. Dell Version: A01, Build# 17630552 [URL]    
Hi, Am planning an upgrade to ESXi 7.0.2 (from 6.7.0) and would like to upgrade the FX2s firmware at the same time. I have a single FX2s with 1x CMC (fw - 2.10.200.201804033862)  (mainboard fw - 1.20.A00.201502058) 2x IOM  (fw 9.11(0.0) ) 3x FC640 blades: BIOS - 1.4.8Integrated Dell Remote Access Controller - 3.21.21.21Lifecycle Controller - 3.21.21.21Dell 32 Bit uEFI Diagnostics - 4301A13Dell OS Driver Pack - 18.04.07CMC - 2.10.200.201804033862QLogic 577xx/578xx 10 Gb Ethernet BCM57810 - - 10.01.00QLogic 577xx/578xx 10 Gb Ethernet BCM57810 - - 10.01.00Backplane 1 - 4.26OS COLLECTOR 3.1iDRAC Service Module Installer 3.0.2System CPLD - 1.0.0   Plan is CMC, main-board and IOM's via file and then running the latest bootable iso in IDRAC for each of the blades 1 at a time.   Questions: 1. Any gotchas going to latest firmware on each?  Do I need to follow any upgrade paths in increments for any components? 2. with only 1 CMC am I able to upgrade that without downtime for the servers (some answers say yes, other documentation indicates no) - does that apply to both CMC and main-board firmware? 3. Can I upgrade 1x IOM at a time without downtime?  (can find nothing on that in documentation). 4. From reading around seems if CMC update fails, then options are - remove and reseat CMC to see if works, if not get a replacement from Dell - any other options if I get stuck?   Previous testing shows we can live with only 2x FC640, but with only 1 CMC am I best just skipping the firmware upgrades altogether?   Thanks for your time.            
FX2s firmware upgrade options