[postgresql] Psql could not connect to server: No such file or directory, 5432 error?

I'm trying to run psql on my Vagrant machine, but I get this error:

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"?

Note: Vagrant 1.9.2 Box: ubuntu/trusty64, https://atlas.hashicorp.com/ubuntu/boxes/trusty64

EDIT Commands I've used in order to install and run postgres:

• sudo apt-get update
• sudo apt-get install postgresql
• sudo su postgres
• psql -d postgres -U postgres

I occasionally have the same issue but mostly after macOS upgrades. Shutting down and migrating to the new version usually fixes it for me(make changes according to your version). So first upgrade your postgresql

brew services stop postgresql@12
brew services start postgresql@12
brew postgresql-upgrade-database

This is mostly a temporary fix but since I couldn't find a better solution this works for me.

Update: If the issue says that another postmaster is running then try removing it from that location(your postmaster.pid location will be displayed to you)

rm /usr/local/var/postgres/postmaster.pid

I had the same issue but non of the answers here helped.

How I fixed it (mac)

• Try to start postgresql with pg_ctl -D /usr/local/var/postgres start
• Look for the Error Message that says something like FATAL: could not open directory "pg_tblspc": No such file or directory.
• Create that missing directory mkdir /usr/local/var/postgres/pg_tblspc
• Repeat from step one until you created all missing directories
• When done and then trying to start postgresql again it might say FATAL: lock file "postmaster.pid" already exists
• Delete postmaster.pid: rm /usr/local/var/postgres/postmaster.pid
• Start postgres with: pg_ctl -D /usr/local/var/postgres start
• Done ?

I was able to solve the issue by running:

sudo systemctl start [email protected]

If non of the above answers are not working for you, then please try this one,

Many people have mentioned many solutions to this problem! But all of them forgot that, the same problem will arise when your disk don't have enough space or the space you are assigned for postgres is full

Check your system storage, if its full free up some space! then restart your postgres by sudo service postgresql restart or do a stop and start sudo service posgresql stop then sudo service postgresql start

This will solve the issue, it solved for me

FATAL:  could not load server certificate file "/etc/ssl/certs/ssl-cert-snakeoil.pem": No such file or directory
LOG:  database system is shut down
pg_ctl: could not start server

I have a missing ssl-cert-snakeoil.pem file so i created it using make-ssl-cert generate-default-snakeoil --force-overwrite And it worked fine.

In my case it was the lockfile postmaster.id that was not deleted properly during the last system crash that caused the issue. Deleting it with sudo rm /usr/local/var/postgres/postmaster.pid and restarting Postgres solved the problem.

The same thing happened to me as I had changed something in the /etc/hosts file. After changing it back to 127.0.0.1 localhost it worked for me.

I have the same issue with postgres 11 on my mac. I get this error every time after restart

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"?

As a temporary fix I do

brew services stop postgresql@11
brew services start postgresql@11

This works for me:

pg_ctl -D /usr/local/var/[email protected] stop;
brew services stop [email protected];
brew services start [email protected];

These two steps solved it for me on Mac:

rm /usr/local/var/postgres/postmaster.pid
brew services restart postgresql

EDIT:

In case you face this issue (reported by @luckyguy73): psql: FATAL: database "postgresql" does not exist

You can run

brew postgresql-upgrade-database

to fix it.

I got this error when I restored my database from last pg_basebackup backup file. After that when I tried to connect database(psql), I was getting the same error. The error was resolved, when I updated pg_hba.conf file and wherever "peer" authentication was there I replaced that with "md5" and then restarted postgres services. After that, the problem was resolved.

I recommend you should clarify port that postgres. In my case I didn't know which port postgres was running on.

lsof -i | grep 'post'

then you can know which port is listening.

psql -U postgres -p "port_in_use"

with port option, might be answer. you can use psql.

This error happened to me after my mac mini got un-plugged (so forced shutdown), and all I had to do to fix it was restart

I'm on Kali Linux. I had to remove the brew version of postgresql with

brew uninstall postgresql

sudo -u postgres psql got me into root postgres

just reinstall your pgsql with direct version sudo apt-get install postgresql-9.5 (u must remove the package before install new one)

Open your database manager and execute this script

update pg_database set datallowconn = 'true' where datname = 'your_database_name';

In my case, I had to run journalctl -xe, and it showed that my disk was full. I then deleted some .gz items from /var/log and I could again restart the postgresql.

Does the /etc/postgresql/9.6/main/postgresql.conf show that port being assigned? On my default Xubuntu Linux install, mine showed port = 5433 for some reason as best as I can remember, but I did comment out the line in that same file that said listen_addresses = 'localhost' and uncommented the line listen_addresses = '*'. So maybe start and check there. Hope that helps.

WARNING: This will remove the database

Within zsh:

rm -rf /usr/local/var/postgres && initdb /usr/local/var/postgres -E utf8

This is the only thing that worked for me after countless hours trouble shooting.

WARNING: This will remove the database

Use command:

rm -rf /usr/local/var/postgres && initdb /usr/local/var/postgres -E utf8

I had the same error when I create the SQL db in a VM. I had changed the default value of /etc/postgresql/9.3/main/postgresql.conf shared_buffers = 200MB to 75% of my total RAM. Well, I forgot to actually allocate that RAM in the VM. When I gave the command to make a new database, I received the same error.

Powered off, gave the baby its bottle (RAM) and presto, it worked.

I am just posting this for anyone who is feeling lost and hopeless as I did when I found this question. It seems that sometimes by editing some psotgresql-related config files, one can accidentally change the permissions of the file:

Note how pg_hba.conf belongs to root, and users cannot even read it. This causes postgres to not be able to open this file and therefore not be able to start the server, throwing the error seen in the original question.

By running

sudo chmod +r pg_hba.conf

I was able to make this file once again accessible to the postgres user and then after running

sudo service postgresql start

Was able to get the server running again.

I had similar problems just a while ago. After trying more than 5 suggestions I decided to go back to the basics and start from the beginning. Which meant removing my postgresql installation and following this guide upon re-installing postgresql. https://help.ubuntu.com/lts/serverguide/postgresql.html