Postgres FATAL: could not open relation mapping file

Question

I installed postgress.app on mac os when I try to connect to console : psql -h localhost I got this problem .

psql -h localhost psql: FATAL: could not open relation mapping file "global/pg_filenode.map": No such file or directory

Any ideas how to solve this ?

• user1822: Did you run initdb?
• user3001937: Yes I did. I am trying now to re-install everything.
• user1822: If the datadir exists, then it's probably a file permission problem. The user running the postgres service probably does not have the rights to access the files (or is looking in the wrong place)
• user3001937: what do you suggest to do ?
• Craig Ringer: Is there data you care about on that database instance? If so read and act on the guidance for database corruption.

Answer 1

I had the same error when I tried to reinstall PostgreSQL on RHEL6 using a Chef cookbook. In my case this seems to have been due to an incorrect manual uninstallation of PostgreSQL. I used this command to find the offending files that disrupted my installation:

find / -user postgres 

And then I deleted all the files I found as they were owned by postgres and I did not even have a postgres user. To be on the safe side I also rebooted the machine and after that it worked like a charm.

Answer 2

In my case this was caused by a running postgresql and me running initdb a few times. Killing all postgresql processes, removing the pgsql/data directory, running initdb and then starting postgresql again solved the issue.