I have recently switched from using Firebird 1.5.4 super server to
classic server in order to take advantage of new hardware with
multi-core processors.

This is my new setup: Firebird Classic Server 1.5.4 running on Redhat
Enterprise Linux Server 5 on a quad core HP DL360 with 4GB ram.

All is running fine, apart from one thing: when I try to restore
databases using the following syntax,

/opt/firebird/bin/gbak -c -r /home/data/mydb.fbk /home/data/mydb.fdb

I get these errors:
gbak: ERROR: I/O error for file ""
gbak: ERROR: Error while trying to open file
gbak: ERROR: no such file or directory
gbak: ERROR: sort error
gbak: ERROR: Exiting before completion due to errors

On super server, I used to (sucessfully) use this syntax:
/opt/firebird/bin/gbak -c -r /home/data/mydb.fbk
localhost:/home/data/mydb.fdb

I understand that, on classic, gbak will be running under the
permissions of the user I am logged in as - which is root in my test
cases. And I have experimented with the file permissions by changing
from root ownership to firebird user ownership (which is what the
fb_inet_server process runs as, but I am having no success.

Has anyone else come across this? What am I doing wrong?

Thanks in advance for any help.

Regards
Richard Salt