--- In firebird-support@yahoogroups.com, Helen Borrie <helebor@...> wrote:

>
> At 12:27 PM 10/04/2008, Adam wrote:
>
>
> >Your understanding of gbak is correct. However if your database file
> >has some corruption, the engine may crash when gbak happens to read
> >that piece of data. If you are using Superserver, then this crash will
> >affect all clients.
>
> Adam, have you ever seen the engine crash when gbak happens to read

corrupt data? Gbak -backup itself can crash but I've never heard of
the server crashing in these circumstances...did you attempt to
reproduce it?

Hi Helen,

Yes. In fact with the one I have seen you can duplicate with an
unrestricted select * query on the effected table. I tried it again to
make sure I am not mad:

.
.
.
.
gbak: writing data for table [CORRUPTTABLE]
gbak: ERROR: internal gds software consistency check (wrong record
length (183))

gbak: ERROR: gds_$receive failed
gbak: Exiting before completion due to errors
gbak: ERROR: internal gds software consistency check (can't continue
after bugcheck)

In firebird.log

LAPPY Thu Apr 10 13:32:58 2008
Database: F:\BACKUP\DATABASE\OTHER\CORRUPT.FDB
internal gds software consistency check (wrong record length (183))

I have also seen one other instance where gbak failed due to the
corruption but was successful with the -g switch (corruption must have
been in a back version).

Adam