[firebird-support] Unable to finish backup with GBK (Firebird 1.5)

[Stih Po Stih stihpos...@yahoo.com [firebird-support]]

I have an old database running on Windows 7 PC with Firebird 1.5, working just 
fine for years (from 2005.).Currently, FDB file is little larger than 700MB.
Now, I decided to update to FB3. Nothing simpler, I thought. Just gbak backup 
with FB1.5 and restore on FB3.
But, I have an issue which I cannot understand. My gbak doesn't report any 
error or failure (log file empty), but when run with -verbose, I just get:gbak: 
160000 records writtengbak: 180000 records writtengbak: 200000 records 
writtengbak: 220000 records writtengbak: 240000 records writtengbak: 260000 
records writtengbak: 280000 records wri
and it breaks - brings me back to terminal. FBK file created is cca 200 MB, but 
cannot be restored - gbak restore (also on FB1.5, just checking the backup) 
asks for another volume etc. So I believe backup is broken.
What would be the path to successfull backup or at least finding the reason why 
it doesn't work as expected?The app using the database works fine, there are no 
errors related to DB...