Whenyou configureSet Startup VersionOnly for an I/O module, the I/O module is rebooted when the
fabricinterconnect in its data path is rebooted. If you do not configure Set Startup VersionOnly for an
I/Omodule, the I/O modulereboots and disruptstraffic. In addition, if Cisco UCS Manager detects a
protocoland firmware version mismatch between the fabric interconnect and the I/O module, Cisco UCS
Managerautomatically updates the I/O module with the firmware version that matches the firmware in
thefabric interconnect and then activates the firmware and reboots the I/O module again.
Caution
Outage Impacts of Direct Firmware Upgrades
Whenyou perform a direct firmware upgrade on an endpoint, you can disrupt traffic or cause an outage in
oneor moreof the endpointsin theCisco UCS domain.
Outage Impact of a Fabric Interconnect Firmware Upgrade
Whenyou upgrade the firmware for a fabricinterconnect, you cause the following outage impacts and
disruptions:
• The fabric interconnect reboots.
• The corresponding I/O modules reboot.
Outage Impact of a Cisco UCS Manager Firmware Upgrade
Afirmware upgrade toCisco UCSManager causes the followingdisruptions:
• Cisco UCS Manager GUI—All users logged in to Cisco UCS Manager GUI are logged out and their
sessionsended.
Anyunsaved work in progress is lost.
• Cisco UCS Manager CLI—All users logged in through telnet are logged out and their sessions ended.
Outage Impact of an I/O Module Firmware Upgrade
Whenyou upgrade the firmware for an I/O module, you cause the following outage impacts and disruptions:
• For a standalone configuration with a single fabric interconnect, datatraffic is disrupted when the I/O
modulereboots. Fora clusterconfiguration with twofabric interconnects,data traffic fails over to the
otherI/O moduleand thefabric interconnectin its data path.
• If you activate the new firmware as the startup version only,the I/O module reboots when the
correspondingfabric interconnectis rebooted.
• If you activate the new firmware as the running and startup version, the I/O module reboots immediately.
• An I/O module can take up to ten minutes to become available after a firmwareupgrade.
Outage Impact of a CIMC Firmware Upgrade
Whenyou upgrade the firmware for a CIMC in a server, you impact only the CIMC and internal processes.
Youdo not interrupt server traffic. This firmware upgrade causes the following outage impactsand disruptions
tothe CIMC:
Cisco UCS Manager GUI Configuration Guide, Release 2.0
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Firmware Upgrades