C:\Programs\Firebird\Avalerion>isql
Use CONNECT or CREATE DATABASE to specify a database
SQL> create database "test";
SQL> create table customer_files (a integer);
SQL> insert into customer_files values(1);
SQL> exit;

C:\Programs\Firebird\Avalerion>gbak -b -v -skip_data customer_files TEST test.bak
gbak:readied database TEST for backup
gbak:creating file test.bak
gbak:starting transaction
gbak:database TEST has a page size of 8192 bytes.
gbak:writing domains
gbak:    writing domain RDB$1
gbak:writing shadow files
gbak:writing character sets
gbak:writing collations
gbak:writing tables
gbak:    writing table CUSTOMER_FILES
gbak:         writing column A
gbak:writing types
gbak:writing filters
gbak:writing id generators
gbak:writing exceptions
gbak:writing functions
gbak:writing stored procedures
gbak:writing packages
gbak:writing triggers
gbak:writing trigger messages
gbak:    writing privilege for user SD
gbak:    writing privilege for user SD
gbak:    writing privilege for user SD
gbak:    writing privilege for user SD
gbak:    writing privilege for user SD
gbak:    writing privilege for user SD
gbak:writing security classes
gbak:writing table constraints
gbak:writing referential constraints
gbak:writing check constraints
gbak:writing SQL roles
gbak:writing names mapping
gbak:closing file, committing, and finishing. 1024 bytes written