Upgrade PSQL

upgrade_psql

apt-get install postgresql-9.3 pgadmin3 postgresql-contrib-9.3 # contrib is needed for hstore

su - postgres
psql -p 5432 -c "\l" # check the collation column and note that (for ex. en_US.UTF8)
psql -p 5433 -c "\l" # If the collation is the same, continue. If not, recreate the 9.3 cluster with the following commands

# Recreate 9.3 cluster with collation from old 9.1 cluster
# pg_ctlcluster 9.3 main stop
# pg_dropcluster 9.3 main
# export LC_ALL="<old-clusters-collation>" # For ex. LC_ALL="en_US.UTF8"
# pg_createcluster 9.3 main

# Stop all running postgresql servers
/etc/init.d/postgresql stop

# Must link conf file into data directory since it's expected there by pg_upgrade.
# Unfortunately, Ubuntu places it in /etc default (which complicates the upgrade)
ln -s /etc/postgresql/9.1/main/postgresql.conf /var/lib/postgresql/9.1/main/postgresql.conf
ln -s /etc/postgresql/9.3/main/postgresql.conf /var/lib/postgresql/9.3/main/postgresql.conf

# Run the pg_upgrade, but as the postgres user instead of root.
su - postgres
/usr/lib/postgresql/9.3/bin/pg_upgrade -d /var/lib/postgresql/9.1/main -D /var/lib/postgresql/9.3/main -b /usr/lib/postgresql/9.1/bin -B /usr/lib/postgresql/9.3/bin -k -v

# Hopefully upgrade finished without error! In which case, we can start up PostgreSQL...
/etc/init.d/postgresql start