Hi
When an upgrade is started we create a directory with the upgrade version name and all the logs related to upgrade will be stored under that folder.
Once you are inside the FTD shell switch to directory /ngfw/var/log/sf/<upgrade version>
in this directory, we will have all the script logs which we ran during the upgrade process.
If you are interested to know the progress then you can do a "tail -f status.log"
Note:- Upgrade version folder will be created only after the successful file push from the FMC.
Thanks
Shuhaib