About the firmware upgrade options
You can upgrade the firmware by using the HPE iLO interface or from the NetBackup Flex Scale web UI.
HPE iLO-based interface: Veritas recommends using the HPE Integrated Lights-Out (iLO) interface for upgrading the firmware. With the HPE iLO interface, you can use any of the following methods to upgrade the firmware:
See Updating the firmware in NetBackup Flex Scale clusters using HPE iLO.
Rolling method: In a rolling firmware upgrade, firmware on each node is upgraded successively.
Parallel method: In a parallel firmware upgrade, firmware on all the nodes is upgraded simultaneously.
NetBackup Flex Scale web UI: You can use the Firmware upgrade option in the UI to upgrade the firmware.
You have an option to do the upgrade using rolling or parallel upgrade method.
See Updating the firmware in NetBackup Flex Scale clusters using the UI.