postgres restore from data files - no data showing up

Question

I am restoring a database which I rather hastily did not pg_dump, I merely tarred the data files themselves. The data files are too old (8.1) to load into the postgres on the machine I am bringing them to, so I compiled (fc14) and installed postgres 8.1 in order to load them in and pg_dump them, to get a dump file to restore in the new db installation.

Everything was going well until I tried to see the data. That is, I start the postmaster with pg_ctl start -D /mypath/mydata and get 'postmaster starting', the server is running and I can connect to it. It's just that the database I expected to see is not there. Attempting to connect to that database tells me it does not exist.

postgres=# \dn
    List of schemas
    Name        |  Owner   
--------------------+----------
 information_schema | postgres
 pg_catalog         | postgres
 pg_toast           | postgres
 public             | postgres
(4 rows)

postgres=# \c ridenetdb
FATAL:  database "ridenetdb" does not exist
Previous connection kept

The only thing I touched in the data files was something called pg_hba.conf, I set all connections to 'trust'. Am I just missing something perhaps, or is this a lost cause?

Answer 1

You might want to check these things:

• Postgres data files are not architecture independent - are you running the same architecture as the original host (virtualization is your friend)
• Postgres data files only work within the same version. Just to be sure get the exactly same version although I believe patchlevel version changes should be compatible

Answer 2

Sorry for the bother - it turned out I had backed up the wrong data tree, so naturally the db wasn't there. Fortunately, that sinking feeling I got when I realized this went away a few minutes later when I discovered I had actually made a text dump of the data anyway. I really need to be more organized...

Just so that this adventure wasn't a total waste of time, I did find out one tidbit that might be useful for anyone drawn to click this question: in the data tree, the file /global/pg_database is a little text file which shows the names of the databases contained.