Synchronize Backup to another remote database

[kah_hang_ang@xxxxxxxxxxxx]

Hi,

Currently we want to upgrade postgresql to 8.1.3 but our current postgresql
database (v7.2.2) is use in the production line so we can't stop the
current database.
So is there any way to synchronize backup the current postgresql database
to another remote postgresql database without interrupt our current
postgresql database?

Thanks.