Am I Getting “Can’t Connect to Local MySQL Server Through Socket ‘/tmp/mysql.sock’” on Tiny Core Linux

Recently, while working on a lightweight LAMP setup on Tiny Core Linux, I ran into a frustrating error while trying to start MariaDB. I assumed a simple mysql start would fire up the database, but instead, I was met with a rather cryptic error message:

ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/tmp/mysql.sock' (2 "No such file or directory")

After a lot of debugging, checking configurations, and experimenting, I finally cracked the issue and learned a lot in the process.

Here’s a detailed breakdown of what went wrong, why, and how I fixed it (plus some bonus functionality to make things smoother in the future).

The First Command I Tried

Like many others, I tried starting MariaDB with:

mysql start

But instead of launching the server, I got hit with:

ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/tmp/mysql.sock' (2 "No such file or directory")

What the Problem Here

The error essentially means:

The MySQL client tried to connect to the MariaDB server using a Unix socket at /tmp/mysql.sock, but that socket doesn’t exist.

This happens because:

• The MariaDB server isn’t running, so the socket file never got created.
• Or the server is configured to create the socket in a different location.
• Or I simply tried to start the client (mysql) instead of the server (mysqld).

My my.cnf Configuration

Here’s the important part of my MariaDB config file:

[client]
socket = /tmp/mysql.sock

[mysqld]
socket = /tmp/mysql.sock

So both the server and client are supposed to use /tmp/mysql.sock. But since the server wasn’t even running, the socket didn’t exist.

Correct Way to Start MariaDB on Tiny Core Linux

This was the real problem. I wasn’t actually starting the server.

Here’s how I correctly started MariaDB:

sudo mysqld --defaults-file=/etc/my.cnf &

Alternatively, if MariaDB was installed with startup scripts:

sudo /usr/local/etc/init.d/mysqld start

Reminder: mysql is the client, not the server. To start the actual service, use mysqld.

Once I did that, /tmp/mysql.sock was created, and the client connected successfully.

Adding a Reusable Startup Script

To streamline things, I wrote a small shell script to handle startup:

#!/bin/sh
# File: /usr/local/bin/start_mysql.sh

if ! pgrep -x "mysqld" > /dev/null
then
    echo "Starting MariaDB server..."
    /usr/local/bin/mysqld --defaults-file=/etc/my.cnf --user=mysql &
else
    echo "MariaDB is already running."
fi

Make it executable:

chmod +x /usr/local/bin/start_mysql.sh

Now I can just run:

sudo /usr/local/bin/start_mysql.sh

Even better, I created an alias for convenience:

alias mysqlstart='sudo /usr/local/bin/start_mysql.sh'

I added that to my .bashrc so it’s always available.

Extra Checks:

Here’s how I verified the server is up and running:

Check the process:

ps aux | grep mysqld

Confirm the socket file exists:

ls -l /tmp/mysql.sock

If it’s missing, locate it:

sudo find / -type s -name "mysql.sock" 2>/dev/null

If the Server Is Running But Socket Is Missing

In one test, the server was running fine but /tmp/mysql.sock still wasn’t being created. This was due to /tmp being reset on reboot or improper permissions.

Change the socket location in my.cnf:

[mysqld]
socket = /var/run/mysqld/mysqld.sock

Then, create the directory and set permissions:

sudo mkdir -p /var/run/mysqld
sudo chown mysql:mysql /var/run/mysqld

Now restart MariaDB and you’re good to go.

Summary

Final Thought

Setting up LAMP on Tiny Core Linux is an awesome project, but it requires understanding the difference between the client (mysql) and the server (mysqld). Most of the time, the error messages are accurate they just assume you know how the architecture works.