On the web page http://www.openmicroscopy.org/site/support/omero4/sysadmins/server-backup-and-restore.html there is an example backup script.
I'm pretty sure this script is broken. It gives the illusion of working, but it's not actually backing up the database.
I believe the actual last line of the script should be:
su $DATABASE_ADMIN -c "pg_dump -Fc -f $OUTPUT_DIRECTORY/$DATABASE.$DATE.pg_dump $DATABASE"
for it to work.
I also think that you should get rid of the first line "#!sh" since that also won't work.
Am I misunderstanding something?