I'm starting up a postgres 9.3 instance on a ubuntu 12.04 server :
~# service postgresql start * The PostgreSQL server failed to start. Please check the log output. [fail] the start fails, but it leaves no log, this file is empty :
tail /var/log/postgresql/postgresql-9.3-main.log and the are no other files in this directory : /var/log/postgresql/
what is the best way to troubleshoot this ?
Try running it manually with debug enabled. This will cause it to run in the foreground and print any error messages to standard error, while also increasing the verbosity.
I believe this will be the correct command line for PostgreSQL 9.3 on Ubuntu, but it might require some very slight tweaking (note: line is split for readability; you can recombine it to a single line (without the backslash) if you want):
/usr/lib/postgresql/9.3/bin/postgres -d 3 -D /var/lib/postgresql/9.3/main \ -c config_file=/etc/postgresql/9.3/main/postgresql.conf The beginning is the location of the postgres binary, then we enable debug and set it to level 3 (you can adjust this up or down to increase or decrease verbosity). Next we specify the data directory and the config file to start with. These should be the defaults for Ubuntu Server 12.04, I think.
Hopefully, that'll give you enough information to determine where the problem is.
service command is just a convenient wrapper around the /etc/init.d/ script that actually starts and stops the process. You'll need to look at that script to see what it's doing differently from when you manually run it. Doing something like bash -x /etc/init.d/postgresql start might be a good place to start your research. Based on the answer of @christopher:
With postgres 12 on ubuntu, I ran:
# with my custom data dir: /usr/lib/postgresql/12/bin/postgres -d 3 -D /media/ssd1/pg_data -c config_file=/etc/postgresql/12/main/postgresql.conf # with default config: /usr/lib/postgresql/12/bin/postgres -d 3 -D /var/lib/postgresql/12/main -c config_file=/etc/postgresql/12/main/postgresql.conf In my case, the issue was the following:
2020-06-02 15:27:45.468 GMT [2522] LOG: skipping missing configuration file "/media/ssd1/pg_data/postgresql.auto.conf" 2020-06-02 17:27:45.469 CEST [2522] FATAL: data directory "/media/ssd1/pg_data" has wrong ownership 2020-06-02 17:27:45.469 CEST [2522] HINT: The server must be started by the user that owns the data directory. 2020-06-02 17:27:45.469 CEST [2522] DEBUG: shmem_exit(1): 0 before_shmem_exit callbacks to make 2020-06-02 17:27:45.469 CEST [2522] DEBUG: shmem_exit(1): 0 on_shmem_exit callbacks to make 2020-06-02 17:27:45.469 CEST [2522] DEBUG: proc_exit(1): 0 callbacks to make 2020-06-02 17:27:45.469 CEST [2522] DEBUG: exit(1) I had no useful info in sudo cat /var/log/postgresql/postgresql-12-main.log And sudo systemctl start postgresql produced no output
sudo -u postgres <command>
su - postgres; /usr/local/pgsql/bin/postgres -D /usr/local/pgsql/dataand see what it gives you. You may need to change user name and paths depending on your setup.-d 3to thepostgrescommand. This will enable more extensive debugging output written to the log. You can lower the debugging output by changing it to 1 or 2, or increase it by changing it to 4 or 5. Also, what is the output ofwhich pgsql?