After backup we do a test restore:

gbak -v -se server_name:service_mgr -use_all_space -r backup.fbk
test.fdb

Normally we just delete the file after gbak completes, but I'd like to
be nicer to the database server. Some coworkers have also been saying
they think that Firebird is still using the database after gbak exits,
and deleting the file at that point is logging errors.

After gbak completes, should I run an isql script and drop the database?
Should I shutdown the database? Or just continue deleting the file
after the restore completes?