Holger,
Once the Ridgeline 4.0 backup is complete, it will be placed in 'x:\Program Files\Extreme Networks\Ridgeline 4.0\database\bin'. A folder will created as specified by the backup name and additionally a sub-folder will be created with the time and date stamp. The file within the sub-folder will be named identically but with an .sql extension. An example is as follows:
To Backup:
C:\Program Files\Extreme Networks\Ridgeline 4.0\database\bin>DBBackupTool.exe backup test4
17:07:05,365 INFO [main][DBUtilityLauncher] Absolute path C:\Program Files\Extreme Networks\Ridgeline 4.0\database\bin\test4\30_04_2014_17_07_05_backup\30_04_2
014_17_07_05_initial.sql
17:07:07,003 INFO [main][DBUtilityLauncher] Successfully created backup in: test4\30_04_2014_17_07_05_backup
Backup File Location:
C:\Program Files\Extreme Networks\Ridgeline 4.0\database\bin\test4\30_04_2014_17_07_05_backup\30_04_2014_17_07_05_backup.sql
The sql file can then be used in the migration to NetSight.