>>> I can't recall if gbak returns an exit error code if something weird
>>> happens,
>> On Linux, it returns zero for all ok and 1 for something bad happened.

On Windows, it also returns an ERRORLEVEL > 0 when something has gone
wrong.

>>> but to check if a backup is valid, the only thing you can do is
>>> to restore the backup and see if this process goes through. This is
>>> something I do for critical databases/backups.

>> Always good advice. There is always a possibility that the backup
>> worked, but the file could still be corrupt. :-(

A Backup can fail when there are physical errors in the database. A
Restore can fail when there are logical errors in the database (like
NULL values on a NOT NULL field). So to be 100 % safe that a database
is intact you must regularly backup AND restore it ...

Regards

Stefan