Can't start MySQL service after permissions issues

Question

I'm hosting a local LAMP server with Magento installed on it (in /var/www/html/magento), which I've had working fine, but I managed to break some things tonight.

I encountered an issue with part of my Magento setup (I honestly don't recall what) that prompted me to run chmod -R -777 /var/ and chown -R travis /var/ to give permissions to all the files within.

This caused Apache 403 errors, which were resolved by me running chmod -R -755 /var/www/ and chown -R root /var/. Further permissions were fixed with chmod -R -777 /var/www/html/magento.

Fastforward to now

I can't start my MySQL service. Here's what I'm getting:

travis@travis: service mysql stop
travis@travis: service mysql start
Job for mysql.service failed. See "systemctl status mysql.service" and "journalctl -xe" for details.
travis@travis:/etc/mysql$ systemctl status mysql.service -l
● mysql.service - MySQL Community Server
Loaded: loaded (/lib/systemd/system/mysql.service; enabled; vendor preset: enabled)
Active: activating (start-post) (Result: exit-code) since Wed 2015-06-17 23:01:24 EDT; 7min ago
Process: 31638 ExecStart=/usr/bin/mysqld_safe (code=exited, status=2)
Process: 31635 ExecStartPre=/usr/share/mysql/mysql-systemd-start pre (code=exited, status=0/SUCCESS)
Main PID: 31638 (code=exited, status=2);         : 31639 (mysql-systemd-s)
CGroup: /system.slice/mysql.service
       └─control
         ├─ 1072 sleep 1
         └─31639 /bin/bash /usr/share/mysql/mysql-systemd-start post

Jun 17 23:01:24 travis systemd[1]: Starting MySQL Community Server...
Jun 17 23:01:24 travis mysqld_safe[31638]: 150617 23:01:24 mysqld_safe Can't log to error log and syslog at the same time.  Remove all --log-error configuration options for --syslog to take effect.
Jun 17 23:01:24 travis mysqld_safe[31638]: 150617 23:01:24 mysqld_safe Logging to '/var/log/mysql/error.log'.
Jun 17 23:01:24 travis mysqld_safe[31638]: touch: cannot touch ‘/var/log/mysql/error.log’: Permission denied
Jun 17 23:01:24 travis mysqld_safe[31638]: chmod: cannot access ‘/var/log/mysql/error.log’: Permission denied
Jun 17 23:01:24 travis mysqld_safe[31638]: 150617 23:01:24 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql
Jun 17 23:01:24 travis mysqld_safe[31638]: /usr/bin/mysqld_safe: 126: /usr/bin/mysqld_safe: cannot create /var/log/mysql/error.log: Permission denied
Jun 17 23:01:24 travis mysqld_safe[31638]: /usr/bin/mysqld_safe: 1: eval: cannot create /var/log/mysql/error.log: Permission denied
Jun 17 23:01:24 travis systemd[1]: mysql.service: main process exited, code=exited, status=2/INVALIDARGUMENT

Now, my Magento site 127.0.0.1/magento/ displays an error page led with:

SQLSTATE[HY000] [2003] Can't connect to MySQL server on '127.0.0.1' (111)

Solution

After a suggestion by cargo, I was able to get things working again by giving permission for the root group to access /var/log/mysql. I then restarted the mysql service with sudo service mysql restart and everything was back to normal.

Comments

[cargo]

The reinstall route would also save from having to go through this with any other program that is going to have permissions errors. Since it looks like our file systems are different enough I am going to delete the solution I got from mine.

[travisw]

Ok, strange (but pleasant) happenings. All I had to do (above what you had posted) was give the root group permission to Access /var/log/mysql. I then ran sudo service mysql restart successfully and everything is intact. If you'd like to repost your solution as an answer, I'd gladly accept to get you the credit you deserve.

[travisw]

Results in the same error with the same log.

[Ayushya]

Ok, I read what happened before the fast-forward ... and that looks bad. Your whole /var permissions have been adjusted. If possible, I would say reinstall the OS.