Bdtjtk

If you're on macOS and installed postgres via homebrew, try restarting it with

brew services restart postgresql

If you're on Ubuntu, you can restart it with either one of these commands

sudo service postgresql restart



sudo /etc/init.d/postgresql restart

None of the above worked for me. I had to reinstall Postgres the following way :

• Uninstall postgresql with brew : brew uninstall postgresql
  


• 
  brew doctor (fix whatever is here)


• brew prune


• 
  

  Remove all Postgres folders :

  
  
  
  
  
  • rm -r /usr/local/var/postgres
  
  
  • rm -r /Users/<username>/Library/Application Support/Postgres
  
  
  
  



• Reinstall postgresql with brew : brew install postgresql



• Start server : brew services start postgresql
  


• You should now have to create your databases... (createdb)

Hello world :)
The best but strange way for me was to do next things.

1) Download postgres93.app or other version. Add this app into /Applications/ folder.

2) Add a row (command) into the file .bash_profile (which is in my home directory):

export PATH=/Applications/Postgres93.app/Contents/MacOS/bin/:$PATH

3) Launch Postgres93.app from /Applications/ folder. It starts a local server (port is "5432" and host is "localhost").

4) After all of this manipulations I was glad to run $ createuser -SRDP user_name and other commands and to see that it worked! Postgres93.app can be made to run every time your system starts.

5) Also if you wanna see your databases graphically you should install PG Commander.app. It's good way to see your postgres DB as pretty data-tables

Of, course, it's helpful only for local server. I will be glad if this instructions help others who has faced with this problem.

This problema has many sources, and thus many answers. I've experienced each one of them.

1) If you have a crash of some sort, removing the /usr/local/var/postgres/postmaster.pid file is probably required as postgres may not have handled it properly. But ensure that no process is running.

2) Craig Ringer has pointed out in other posts that Apple's bundling of postgreSQL leads to pg gem installation issues Setting the PATH environment variable is a solution.

3) Another solution, is to uninstall and reinstall the gem. A brew update may be necessary as well.

If you stumble upon this post, if you can pinpoint one of the sources, you'll save time...

if your postmaster.pid is gone and you can't restart or anything, do this:

pg_ctl -D /usr/local/var/postgres -l /usr/local/var/postgres/server.log start

as explained here initially

Maybe this is unrelated but a similar error appears when you upgrade postgre to a major version using brew; using brew info postgresql found out this that helped:

To migrate existing data from a previous major version of PostgreSQL run:

brew postgresql-upgrade-database

I was facing a similar issue here I solved this issue as below.

Actually the postgres process is dead, to see the status of postgres run the following command

sudo /etc/init.d/postgres status

It will says the process is dead`just start the process

sudo /etc/init.d/postgres start

For me, the solution was simply restart my computer. I first tried restarting with Brew services and when that didn't work, restarting seemed like the next best option to try before looking into some of the more involved solutions. Everything worked as it should after.

My problem ended up being that I was using Gas Mask (a hosts file manager for Mac), and I didn't have an entry for localhost in the hosts file I was using.

I added:

127.0.0.1 localhost

And that resolved my problem.

This happened to me after my Mac (High Sierra) froze and I had to manually restart it (press and hold the power button). All I had to do to fix it was do a clean restart.

I had the same issue.
Most of the times, the problem is the fact that there's a leftover file

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

which works for most people, but my case was different - I tried googling this issue for last 3 hours, uninstalled postresql on OSX through brew, purged the database, nothing worked.

Finally, I noticed that I had an issue with brew that whenever I tried to install anything, it popped:

Error: Permission denied @ rb_sysopen - /private/tmp/github_api_....

or something like it at the end of an install.

I simply did sudo chmod -R 777 /private/tmp and it finally works!

I'm writing this down because this might be a solution for someone else

I've had to look up this post several times to solve this issue. There's another fix, which will also applies to similar issues with other running programs.

I just discovered you can use the following two commands.

$top

This will show all the currently running actions with their pid numbers. When you find postgres and the associated pid

$kill pid_number

I just got the same issue as I have put my machine(ubuntu) for update and got below error:

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"?

After completing the updating process when I restart my system error gone. And its work like charm as before.. I guess this was happened as pg was updating and another process started.

SUPER NEWBIE ALERT: I'm just learning web development and the particular tutorial I was following mentioned I have to install Postgres but didn't actually mention I have to run it as well... Once I opened the Postgres application everything was fine and dandy.

@Jagdish Barabari's answer gave me the clue I needed to resolve this. Turns out there were two versions of postgresql installed while only one was running. Purging all postgresql files and reinstalling the latest version resolved this issue for me.

The causes of this error are many so first locate your log file and check it for clues. It might be at /usr/local/var/log/postgres.log or /usr/local/var/postgres/server.log or possibly elsewhere. If you installed with Homebrew you can find the location in ~/Library/LaunchAgents/homebrew.mxcl.postgresql.plist.

I'm not entirely sure why, but my Postgres installation got a little bit screwed and some files were deleted resulting in the error OP is showing.

Despite the fact that I am able to run commands like brew service retart postgres and see the proper messages, this error persisted.

I went through the postgres documentation and found that my file /usr/local/var/postgres was totally empty. So I ran the following:

initdb /usr/local/var/postgres

It seems some configurations took place with that command.

Then it asked me to run this:

postgres -D /usr/local/var/postgres

And that told me a postmaster.pid file already exists.

I just needed to know if brew would be able to pick up the configs I just ran, so I tested it out.

ls /usr/local/var/postgres

That showed me a postmaster.pid file. I then did brew services stop postgresql, and the postmaster.pid file disappeared. Then I did brew services start postgresql, and VIOLA, the file reappeared.

Then I went ahead and ran my app, which did in fact find the server, however my databases seem to be gone.

Although I know that they may not be gone at all - the new initialization I did may have created a new data_area, and the old one isn't being pointed to. I'd have to look at where that's at and point it back over or just create my databases again.

Hope this helps! Reading the postgres docs helped me a lot. I hate reading answers that are like "Paste this in it works!" because I don't know what the hell is happening and why.