Postgresql database backup (and restore) from two servers to third storage place
I would run the backup jobs on A and B at specified times using the local native pg_dump, then push them to C for storage.

sudo su -c 'pg_dump -f ~/backupfile.sql -C "MyDB"' myuserid
scp ~/backupfile.sql myuserid@cmachine.mydomain.com:


Restoring from the backup file can be done with:

psql -d &lt;database&gt; -f backup-file.sql