OverviewFor various reason, it might be necessary to downgrade an Exinda appliance's firmware to a previously run version. While this is possible, downgrading firmware is only supported when you are downgrading to a version of the firmware that had previously run on the appliance. There are three possible ways to 'downgrade' the firmware:
- Switch boot partitions to another firmware version that is installed
- Remanufacture the appliance
- Reinstall an older firmware version on a partition.
The second case can be done by following the instructions for remanufacturing an appliance. This will remove all configuration and historical data, and completely create a brand new device on the firmware version that is chosen.
In the last case, please note that it is possible that the configuration and historical data of the device can also be lost due to corruption that happens upon boot. There can be cases where after reinstalling the older firmware version to a partition, the device will refuse to boot into that partition, even if it is selected to boot 'next'. This is because the device gets into a confused state with respect to how the database is configured and automatically falls back to the upgraded partition to successfully boot up. This is unlike the first case, where the original firmware's database still exists. If this happens, Exinda TAC must be contacted. This is not recommended unless absolutely necessary; a remanufacture of the device can achieve the same results and do so in a much cleaner fashion without remnants from any upgrade or downgrade.
Internal NotesIn the case where they reinstalled an older image on the device and tried to boot to it but were unable - database configuration is most likely confused.
We can use the command:
no boot next fallback-reboot enable
This forces the next partition not to boot into the original partition on failure. This is a restricted license command that the end user cannot do on their own; one must be installed on the system. If this is done through SSH, access will be lost on boot as there will be no configuration on the device, including no management IP.
Also note - they can only downgrade to currently supported versions