MySQL Permissions Messed

linuxgeek0 · 09-06-2012, 08:33 AM

Hello everyone!

I am a linux newbie, working on centos & unbuntu ( backtrack) these days.

i have setup a small internal web development server on centos 6.3. LAMP is installed and everything was working fine except vnc freeze problem.

Today what i did is changed the /var directory owner to vnc (a normal user) from root. I also clicked on "Apply Permissions to Enclosed Files"

After that smb,nmb httpd and mysql went down these are the services which I noticed down. I was unable to start these services so what I did is i changed /var owner back to root and i clicked Apply Permissions to Enclosed Files button again :/.

Now my HTTPD, smb and nmb is up and working file. By MySQL failed.

These are the logs.

Code:

[root@dev-server /]# /etc/init.d/mysqld restart
Stopping mysqld:                                           [  OK  ]
MySQL Daemon failed to start.
Starting mysqld:                                           [FAILED]

and my mysqld.log file

Code:

/usr/libexec/mysqld: Can't create/write to file '/tmp/ibk288R4' (Errcode: 13)
120906 16:57:45  InnoDB: Error: unable to create temporary file; errno: 13
120906 16:57:45 [ERROR] Plugin 'InnoDB' init function returned error.
120906 16:57:45 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.
120906 16:57:45 [ERROR] /usr/libexec/mysqld: Can't create/write to file '/var/run/mysqld/mysqld.pid' (Errcode: 13)
120906 16:57:45 [ERROR] Can't start server: can't create PID file: Permission denied
120906 16:57:45 mysqld_safe mysqld from pid file /var/run/mysqld/mysqld.pid ended
120906 16:59:22 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql
/usr/libexec/mysqld: Can't create/write to file '/tmp/ibhSLvlO' (Errcode: 13)
120906 16:59:22  InnoDB: Error: unable to create temporary file; errno: 13
120906 16:59:22 [ERROR] Plugin 'InnoDB' init function returned error.
120906 16:59:22 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.
120906 16:59:22 [ERROR] /usr/libexec/mysqld: Can't create/write to file '/var/run/mysqld/mysqld.pid' (Errcode: 13)
120906 16:59:22 [ERROR] Can't start server: can't create PID file: Permission denied
120906 16:59:22 mysqld_safe mysqld from pid file /var/run/mysqld/mysqld.pid ended
120906 17:05:56 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql
/usr/libexec/mysqld: Can't create/write to file '/tmp/iboxr0rA' (Errcode: 13)
120906 17:05:56  InnoDB: Error: unable to create temporary file; errno: 13
120906 17:05:56 [ERROR] Plugin 'InnoDB' init function returned error.
120906 17:05:56 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.
120906 17:05:56 [ERROR] /usr/libexec/mysqld: Can't create/write to file '/var/run/mysqld/mysqld.pid' (Errcode: 13)
120906 17:05:56 [ERROR] Can't start server: can't create PID file: Permission denied
120906 17:05:56 mysqld_safe mysqld from pid file /var/run/mysqld/mysqld.pid ended
[root@dev-server log]# cat mysqld.log

While accessing phpmyadmin

Code:

phpMyAdmin - Error

Cannot start session without errors, please check errors given in your PHP and/or webserver log file and configure your PHP installation properly.

Now i have no idea how to reset the permissions back. I have 4 mysql dbs with important data. So unistalling and installing back would be the last option.

Thanks.

yancek · 09-06-2012, 09:34 AM

Change the owner:group for /var/lib/mysql and sub-directories to mysql:mysql to start and see if that helps.
Change to /var/lib/ directory as root and run the command: chown -R mysql:mysql mysql/

linuxgeek0 · 09-08-2012, 12:47 AM

Quote:

Originally Posted by yancek

Change the owner:group for /var/lib/mysql and sub-directories to mysql:mysql to start and see if that helps.
Change to /var/lib/ directory as root and run the command: chown -R mysql:mysql mysql/

Before this.

I tried changed these permissions:

Code:

sudo chgrp mysql /var/run/mysqld/
sudo chmod g+w /var/run/mysqld/

(this file was not there so i created it)
sudo chgrp mysql /var/run/mysqld/mysqld.pid
sudo chmod g+w /var/run/mysqld/mysqld.pid

mysqld.log

Code:

120908 09:34:21 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql
120908  9:34:21  InnoDB: Initializing buffer pool, size = 8.0M
120908  9:34:21  InnoDB: Completed initialization of buffer pool
120908  9:34:22  InnoDB: Started; log sequence number 0 322798698
120908  9:34:22 [ERROR] /usr/libexec/mysqld: Can't create/write to file '/var/run/mysqld/mysqld.pid' (Errcode: 13)
120908  9:34:22 [ERROR] Can't start server: can't create PID file: Permission denied
120908 09:34:22 mysqld_safe mysqld from pid file /var/run/mysqld/mysqld.pid ended

after changing permissions i had some luck. but still errcode:13 is there. What yancek suggested is not making any difference in the log. May be it is somthing with /usr/libexec/mysqld right now mysqld permission is mysql:mysql

linuxgeek0 · 09-08-2012, 01:21 AM

I changed these permissions

Code:

chmod 755 /var/run
chmod 755 /var/run/mysqld

and that did the trick

Code:

Starting mysqld:                                           [  OK  ]

Now all websites are working but I am still unable to access phpmyadmin.

Code:

phpMyAdmin - Error

Cannot start session without errors, please check errors given in your PHP and/or webserver log file and configure your PHP installation properly.