my production databases run on a centos 5.5 virtual machine. This server has 2 postgres 8.4 clusters installed on 2 different partitions; now my idea is to upgrade both db version and server os (centos 6) in order to set up a newer machine with also much more disk space. In this way i will be covered for many years. I read postgres documentation and pg_upgrade seems to be a very useful tool but,if i understood well, it can be used only on same machine and on same mounting point. So how can i get my goal? pgdumpall command? note that clusters' sizes are (at the moment) 10gb and 1gb ,but cluster 1 grows up quite fast.