Postgresql-8.4: File System Level Backup (& recovery failure)

Hi all!

I'm trying to recover my database from a file system backup (as
decribed at #24.2 of Postgresql 8.4 Documentation).

WHile the files in the backup directory are owned by
'postgres.postgres', when they are extracted from the backup.tar the
owner becomes 'avahi.haldaemon' or ('messagebus.ssh' if they are copied
directly from backup dir to a new one).
I do change file ownership to postgres.postgres but cannot see any of
the tables and get a void 'mydb' only!

As I am not sure to have stopped the postgres server *before* making the
original copy to the backup dir, is there any chance for me to:
1. ascertain that the backup was made while postgres was running and
   therefore it's completely useless;
2. make sure that failure to recover has nothing to do with the version
   of postgresql-client. AAMOF, I've lost access to original database
   tables after removing postgresql-client-9.1 in the believe it was
   redundant: I had previously downgraded to version 8.4 after having
   the problem as exposed in my post of Oct 17 "WARNING: psql version
   8.4, server version 9.1" unluckily unanswered and not getting any
   further warning I was convinced to be runnning everithing on 8.4;
3. make sure there is no possibility to recover old data this way and
   use an older db.dump (which, of course, would be the easiest way, but
   would leave me with so many doubts pending....)

Thanks for your attention,
     Ennio
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