how migrate data postgres 8.4 to 9.1

Question

Hello,

is there precaution or procedure to migrate database from postgres 8.4 to 9.1

I want to test nuxeo 5.6 on a newer install.
I using in production nuxeo 5.5 on ubuntu 10.04 with postgres 8.4
VM5.6 in test propose ubuntu 12.04 with postgres 9.1 (recommended)

I mean it's a good opportunities to test migration to last supported software.

thanks for your return of experience.
etien

Sun_Seng_David_ · Accepted Answer

You can either

* perform a pg_dump (version 9.1) remotely onto the running 8.4
or
* use pg_upgrade http://www.postgresql.org/docs/9.1/static/pgupgrade.html

I tried both and it works pretty fine