help... lost database after upgrade from 9.0 to 9.1

Hello!

just made a stupid move... upgraded a working system.... and without
checking if the backup was ok....

so i end up with a debian system having upgraded to 9,1 without
converting the database, and a scrambled backup which is totally
unusable....

i tried to start the old tree with                                                          
pg_ctlcluster 9.0 main start                                                                
Error: could not exec   start -D /var/lib/postgresql/9.0/main -l                            
+/var/log/postgresql/postgresql-9.0-main.log -s -o  -c                                      
+config_file="/etc/postgresql/9.0/main/postgresql.conf" :                                   

so i tried to copy the old 9.0 tree to a machine with a still working 9,0
postgres, but it stops with
Starting PostgreSQL 9.0 database server: mainError: could not exec
/usr/lib/postgresql/9.0/bin/pg_ctl /usr/lib/postgresql/9.0/bin/pg_ctl
start -D /var/lib/postgresql/9.0/main -l
/var/log/postgresql/postgresql-9.0-main.log -s -o -c
config_file="/etc/postgresql/9.0/main/postgresql.conf" : ... failed!
failed!
so what can i do to extract the data of that tree and feed it into the
9.1 tree?

thanks in avance!
--
ciao bboett
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bboett@adlp.org
http://inforezo.u-strasbg.fr/~bboett/
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