There are some very important points to consider when discussing backups, not only for the database but also for customized files on the server.
Database backups are essential, nearly all IdentityIQ configuration (identities, roles, rules, workflows, certifications etc.) is stored in the database.
Server file backups should include all customizations, such as files under WEB-INF, custom, scripts, configuration files (like identityiq.properties), and any other custom code.
Before performing any upgrade, it is critical to back up all the items mentioned above, as stated in SailPoint documentation, since application files are overwritten during the upgrade process.
About the recovery process typically involves restoring the database and the customized files, followed by restarting the application.
Server snapshots can be helpful, but they do not replace consistent and proper database and filesystem backups.
Part of the installation documentation:
”Back up your IdentityIQ database and any customization you performed on the current installation. Any customization involving additions or changes to files in the IdentityIQ installation directory is overwritten by the upgrade procedure and will need to be reapplied when it is complete.”
Could you please change the ‘accepted solution’ mark? It should be moved to @LydiaLu 's first or second comment, as those contain the actual fix/information about backup and restore.