When you are upgrading from 9.1 or previous versions to 10.1, only the Snort rules for which validation results are Success or Warning are carried forward from the older version to the new version.
During the upgrade process, the Manager takes a backup of the existing rules in the <Manager Installation Directory>\McAfee\Network Security Manager\App\NSM_SnortrulesBackup_Pre_<NSM Version after upgrade>.rules file. You can use the backup for future reference. For example, if you are upgrading to version 9.2.7.1.45, the backup file will be NSM_SnortrulesBackup_Pre_9.2.7.1.45.rules.
Tip
Before upgrading, if there are any rules in the Failed state in the existing version, it is recommended that you delete the failed rules and then perform the upgrade. If you want the failed rules in the 9.2 version, add them again.