ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/run/mysqld/mysqld.sock' (2) with MariaDB & MySQL

General system Applications
#1

Hi,

I’m using the latest, fully upgraded EndeavourOS. I have installed MySQL and replaced it with MariaDB and have failed to get either to work. I consistently get the error of:

ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/run/mysqld/mysqld.sock' (2)

Here is the output when I run mysqld --verbose:

2020-07-31 17:29:52 0 [Note] mysqld (mysqld 10.4.13-MariaDB) starting as process 11330 ...
2020-07-31 17:29:52 0 [Warning] Can't create test file /var/lib/mysql/username.lower-test
mysqld: Can't change dir to '/var/lib/mysql/' (Errcode: 13 "Permission denied")
2020-07-31 17:29:52 0 [ERROR] Aborting

Running sudo systemctl start mariadb.service, I got the following error log: https://pastebin.com/J7wFh5nR (put in a pastebin because its otherwise quite long)

I have tried various solutions from online, including from these following links:

I had this issue when I had installed MySQL as well. Let me know if there are any other things I should post here.

#2

Hello @MagusZ

Don’t know much about MariaDB but it looks like the service needs to be started.

sudo systemctl start mariadb.service

sudo systemctl enable mariadb.service

Edit: Probably the same issue with MySQL

#3

I tried this and got this error:

Failed to start maraidb.service: Unit maraidb.service not found.

I then tried reinstalling mariadb and the issue wasn’t fixed.

#4

Check spelling! marai != maria …

1 Like
#5 
[ERROR] InnoDB: Plugin initialization aborted with error Data structure corruption

Remove the MySQL database files from /var/lib/mysql and reinitialise using mariadb-install-db (https://wiki.archlinux.org/index.php/MariaDB#Installation).

1 Like
#6

@MagusZ
Ya sorry i misspelled it. My bad! :roll_eyes:

#7

This happens to me sometimes when a mariadb update occurs.
In my case the issue is usually within the service file itself. Check the user running the service:

$ cat /usr/lib/systemd/system/mariadb.service

capture-200801-031604
capture-200801-031604883×308 55.8 KB

Then check if that user has read/write rights to the folder/file mentioned in the error.
Also if your database files are located somewhere other than the default, check that the datadir=[database_files_path] is correctly set up in /etc/my.conf
Sometimes the file gets overwritten on updates.
If it’s set to a folder in your /home /run/user /usr /boot or /etc directory make sure to allow this by setting the ProtectHome or ProtectSystem parameters to false in the service file (/usr/lib/systemd/system/mariadb.service):
capture-200801-032401

#8

Two points:

  1. If it gets overwritten then there’s an issue with the upgrade; old config files should at least be saved as a .pacsave.
  2. Putting customisation under /etc/my.cnf.d/ will avoid editing package-installed files. :wink:
#9

Well then, in my case it’s probably a consequence of using a symlink to a file in my home directory instead of an actual /etc/my.conf file. I like to have all my config files in one place under my home folder, so I can reuse everything on re-installs. Same with the database files.
However the mariadb.service file I can confirm it sometimes gets overwritten by updates (that one I haven’t symlinked).

1 Like
#10

That sounds reasonable - service files aren’t “meant” to be edited, so won’t be in the PKGBUILD’s backup array (also linked below).

systemctl edit mariadb is a good way to override elements of a unit’s behaviour which won’t be removed when the service file is upgraded.

#11

That’s what I was telling myself until I noticed that there are a few settings in the service file that IMO belong into the my.cnf file. Like the two parameters I mentioned in the previous post.

Interesting. Never heard of systemctl edit before. I never stop learning.

2 Likes
#12

Hi, thanks so much for all the help!

@nate I had already done what you had suggested beforehand with the ProtectHome etc. It still gave the same error running mysqld --verbose.

@jonathon I had a pacsave. I reconverted the file to a regular file, this likely was a bad idea. Forgive my newness to this. I also did try moving things around as specified in the links I had put. I will try systemctl edit mariadb and see how it goes. I haven’t tried removing the mysql files yet because I’m not sure what to remove (I’m completely new to MariaDB and am installing it to learn how to use it), should I remove everything in the directory?

#13

Yes,

#14

I removed everything and tried it and am getting the same error, as you can see here: https://pastebin.com/9RbBvgxb

#15

That’s a different error.

This:

indicates a permissions issue.

Possibly you’re trying to run the initialisation steps as your normal user rather than e.g. root (or using sudo).

This:

tells you where to look for more information.

Have you read the MariaDB installation steps on the Arch wiki page?

#16

First off, apologies for me being as dumb with this as I am. I did what you said, followed the Arch Wiki guide, and was now finally able to start the service. I then ran sudo chmod 755 for the folder and it seemingly went through but did not fix the issue.

#17

What issue are you trying to solve by doing that?