MySQL Startup Failing/Hanging in 10.04

[Thomas Gutzmann]

Hi,

After upgrading to Ubuntu 10.04, MySQL wouldn't start up again. Several solutions had been discussed in this forum, but none of them would fit in my situation. I finally found a way which I want to outline here.

Symptom: "start mysql" or "service mysql start" (as root) hangs.

Reason: In /etc/init/mysql.conf, there is an infinite loop in the post-start script due to an incomplete migration of MySQL.

Fix: Create an additional user in the schema "mysql".

Steps:

1. Look at /etc/mysql/debian.cnf. Extract the cryptic, bun unencrypted password for user "debian-sys-maint".
2. Start mysql using "/usr/sbin/mysqld" (as root).
3. Log in as mysql (or "su - mysql").
4. Connect to mysql as root: "mysql -u root --password=XXXX".
5. Create the user "debian-sys-maint", using the password retrieved in step 1: "create user 'debian-sys-maint' identified by 'btIgH81mUXcfZdCQ';".
6. Get the pid of mysqld: "ps ax | grep -i mysqld". Example: "3024 ? Ssl 0:00 /usr/sbin/mysqld"
7. Kill this process: "kill -5 3024".
8. Start mysql (as root): "start mysql". Eventually you see an error message that mysql is already running; this can happen if you tried the command before and cancelled it with control-c. In this case, enter "stop mysql" and "start mysql".
9. Reboot to see if MySQL starts up automatically.
10. If the automatic startup still fails, you may follow the advice from a different thread: change the start condition in /etc/init/mysql.conf to "start on (net-device-up IFACE=ethX)", where "X" is the interface you have mysql bound to, e.g. ETH1.
11. In my case, I had another very specific problem: I'm running Ubuntu in a VM with several virtual disks which were not mounted yet when the network was up. Quite tricky to figure out. So I modified the start condition to "start on (net-device-up IFACE=eth1 and stopped mountall)", and now everything is fine.

Det var det det!

Cheers,

Thomas

[atmorell]

Good work / godt arbejde

[Jordan Rusev]

Hello,
I have the same problem in 10.04. I try to follow this steps, but when I start /usr/sbin/mysqld as root, it failed with messages:

100509 14:36:53 [ERROR] Fatal error: Please read "Security" section of the manual to find out how to run mysqld as root!

100509 14:36:53 [ERROR] Aborting

100509 14:36:53 [Note] /usr/sbin/mysqld: Shutdown complete

and it's impossible to finish your instructions and start MySQL.

[Thomas Gutzmann]

Hi Jordan,

Please have a look at http://dev.mysql.com/doc/mysql-secur...st-attack.html.

My guess is that in your /etc/mysql/my.cnf in section [mysqld] you have

user = root

Change this to

user = mysql

If you have still problems, give me your my.cnf. You should also capture the messages in /var/log/messages while you run "start mysql" or "/usr/sbin/mysql" and include it, too.

Cheers,

Thomas

[blaze042]

That's some great detective work there.

That fixed the hangs when trying to start/stop the service. And it fixed the "ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)" message whenever I tried running mysql.

And Webmin is able to administer the database. Thanks!

[fishgoat]

Hello,

I had the same problem: infinite loop in "post-start script" in /etc/init/mysql.conf
Reason was a incorrect path to the socket in /etc/mysql/debian.cnf (there are two lines "socket = ..."!)
After correctiing the pathes everything worked fine.

[arizonanoob]

Hi,

After upgrading to Ubuntu 10.04, MySQL wouldn't start up again. Several solutions had been discussed in this forum, but none of them would fit in my situation. I finally found a way which I want to outline here.

Symptom: "start mysql" or "service mysql start" (as root) hangs.

Reason: In /etc/init/mysql.conf, there is an infinite loop in the post-start script due to an incomplete migration of MySQL.

Fix: Create an additional user in the schema "mysql".

Steps:

1. Look at /etc/mysql/debian.cnf. Extract the cryptic, bun unencrypted password for user "debian-sys-maint".
2. Start mysql using "/usr/sbin/mysqld" (as root).
3. Log in as mysql (or "su - mysql").
4. Connect to mysql as root: "mysql -u root --password=XXXX".
5. Create the user "debian-sys-maint", using the password retrieved in step 1: "create user 'debian-sys-maint' identified by 'btIgH81mUXcfZdCQ';".
6. Get the pid of mysqld: "ps ax | grep -i mysqld". Example: "3024 ? Ssl 0:00 /usr/sbin/mysqld"
7. Kill this process: "kill -5 3024".
8. Start mysql (as root): "start mysql". Eventually you see an error message that mysql is already running; this can happen if you tried the command before and cancelled it with control-c. In this case, enter "stop mysql" and "start mysql".
9. Reboot to see if MySQL starts up automatically.
10. If the automatic startup still fails, you may follow the advice from a different thread: change the start condition in /etc/init/mysql.conf to "start on (net-device-up IFACE=ethX)", where "X" is the interface you have mysql bound to, e.g. ETH1.
11. In my case, I had another very specific problem: I'm running Ubuntu in a VM with several virtual disks which were not mounted yet when the network was up. Quite tricky to figure out. So I modified the start condition to "start on (net-device-up IFACE=eth1 and stopped mountall)", and now everything is fine.

Det var det det!

Cheers,

Thomas

This could very well be a fix, however, I am not allowed to edit debian.cnf as it is owned by root. Any ideas on how to get around that?

EDIT: nevermind - figured it out via
sudo gedit debian.cnf