Re: Dumping data using pg_dump after chrooting to a different partition

On 10/24/11 3:10 PM, Krishnamurthy Radhakrishnan wrote:
> Hi,
>
> I am new to PostgreSQL. We are using PostgreSQL 9.0.2 on our linux server. We have an instance of PostgreSQL 9.0 running using the primary partition on the server.
>
> We want to use the pg_dump and psql programs to migrate the data during our software upgrade process. For upgrade, we plan to do the following:
>
> * chroot to a secondary partition on the server.
> * install the software RPMs including PostgreSQL RPMs
> * start a secondary instance of PostgreSQL DB server using a different port and data directory.
> * run pg_dump to dump the data from the primary instance to a file.
> * run psql to import the data from the file into the secondary instance.
>
> However when I tried to perform the pg_dump as mentioned above, I get the following error:
> pg_dump: [archiver (db)] connection to database "TestDB" failed: could not connect to server: No such file or directory|<LVL::Debug>
> Is the server running locally and accepting|<LVL::Debug>
> connections on Unix domain socket "/tmp/.s.PGSQL.5432"?|<LVL::Debug>
I suspect the problem is that localhost sockets on Unix/Linux are actual implemented as file-system sockets rather than TCP/IP sockets. If you do chroot, those files won't exist. Try connecting using a "-h hostname (e.g. -h myserver.domain.com) rather than the default localhost. You may have to reconfigure your server to listen on port 80.

Craig