Firebird error during backup - firebird

Question

i want to backup firebird database. Below is command that i use to execute the backup.
gbak -b -v -user SYSDBA -pass ***** -service localhost:service_mgr -verify -y E:/logs/backup_20111104.log D:\data\campaign.FDB E:/backup/campaign_20111104.fbk -FIX_FSS_METADATA WIN1252 -FIX_FSS_DATA WIN1252
However, after 2 hours running, it ends with general error(only in last line). Below is the error.
gbak:22068 records written
gbak: writing data for table AA_1307265720107_842
gbak:19872 records written
gbak: writing data for table AA_1301338383915_1025
gbak:4 records written
gbak:Exiting before completion due to errors
There is 700+ tables in this database. And the database size is 129GB.
I need to get complete stacktrace(if any). Or any idea where to check so i can know the actual error?

Answer 1

Try to repair the database before backup:
gfix -mend -full -ignore <db name> -user sysdba -pas masterkey
While backing up add two switches -g -ig in order to prohibit garbage collection and ignore check sum errors.

Answer 2

Consult the gfix manual section Database Validation and Recovery.
Full Validation
By default, validation works at page level. If no need to go deeper and validate at the record level as well, the command to do this is:
gfix -v[alidate] -full database_name
using this option will validate, report and update at both page and record level. Any corrupted structures etc will be fixed.
[...]
Database Recovery
If the database validation described above produces no output then the database structures can be assumed to be valid. However, in the event that errors are reported, you may have to repair the database before it can be used again.
Recover a Corrupt Database
The option required to fix a corrupted database is the gfix -m[end] command. However, it cannot fix all problems and may result in a loss of data. It all depends on the level of corruption detected. The command is:
gfix -m[end] database_name
This causes the corruptions in data records to be ignored. While this sounds like a good thing, it is not. Subsequent database actions (such as taking a backup) will not include the corrupted records, leading to data loss.
Important
The best way to avoid data loss is to make sure that you have enough regular backups of your database and to regularly carry out test restorations. There is no point taking backups every night, for example, if they cannot be used when required. Test always and frequently.
Equally, when attempting to recover a potentially corrupted database, always work with a copy of the main database file and never with the original. Using the -mend option can lead to silent deletions of data because gfix doesn't care about internal database constraints like foreign keys etc, the -mend option simply says to gfix "go ahead and clean out anything you don't like".
These are the most important points of this section, but make sure to read the entire chapter. If you need additional support, on the Firebird-support list there are a number of people familiar with the ins and outs of Firebird and how to handle these kinds of errors.