Postgres psql: could not connect to server error

Would like to share postgres error , which I happen to notice on psql (9.2). It is sort of weird and I was not able to initiate any database connections.

psql: could not connect to server: No such file or directory

Is the server running locally and accepting

connections on Unix domain socket "/var/run/postgresql/.s.PGSQL.5432"?

I happened to check database was down.

[root@sajidserver ~]# ps -ef|grep pg

root       4152   4238  0 12:43 pts/2    00:00:00 grep --color=auto pg

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 Fix:

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[root@sajidserver ~]$ cd /u01/pgsql/data

[root@sajidserver ~]$ cp postmaster.pid postmaster.pid.bkp

[root@sajidserver ~]$ rm postmaster.pid

Sweet and cool to see DB is back up and running

[root@sajidserver ~]# ps -ef|grep pg

root       4152   4238  0 13:43 pts/2    00:00:00 grep --color=auto pg

postgres  21453      1  0 oct19 ?        00:01:00 postgres -D /u01/pgsql/data