I've screwed up my Lamp server

Wim Sturkenboom · 09-03-2012, 08:47 PM

Ubuntu systems with mysql installed have a special mysql user for update purposes that you can use to login and do maintenance.

With the mysql daemon running, in a terminal

Code:

mysql -u debian-sys-maint -p

In another terminal, 'cat' the file /etc/mysql/debian.cnf. That file contains the password for the debian-sys-masint user; paste that password when prompted for it.

You should now have gained access and this user has the same privileges as the root user.

Assuming the mysql root user is still existing, you can set a password using

Code:

update user set password=password('yourpassword') where user='root'

If the mysql root user no longer exists, use below to create the account

Code:

grant all privileges on *.* to 'root'@'localhost' identified by 'yourpassword' with grant option

Don't forget to flush the privileges before quiting the client.

PS
Not sure how much damage has been done by now, but above would work on a 'normal' install.

southpointingchariot · 09-03-2012, 08:52 PM

Quote:

Originally Posted by Wim Sturkenboom

Ubuntu systems with mysql installed have a special mysql user for update purposes that you can use to login and do maintenance.

With the mysql daemon running, in a terminal

Code:

mysql -u debian-sys-maint -p

In another terminal, 'cat' the file /etc/mysql/debian.cnf. That file contains the password for the debian-sys-masint user; paste that password when prompted for it.

You should now have gained access and this user has the same privileges as the root user.

Assuming the mysql root user is still existing, you can set a password using

Code:

update user set password=password('yourpassword') where user='root'

If the mysql root user no longer exists, use below to create the account

Code:

grant all privileges on *.* to 'root'@'localhost' identified by 'yourpassword' with grant option

Don't forget to flush the privileges before quiting the client.

PS
Not sure how much damage has been done by now, but above would work on a 'normal' install.

When I run "mysql -u debian-sys-maint -p" I get "ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)"

As to the amount of damage, its probably a lot

sag47 · 09-03-2012, 08:53 PM

Quote:

Originally Posted by southpointingchariot

Alas, we have a problem on the earlier step. When I run "service mysql start", I get "start: Job failed to start"

Does /var/log/mysql.err or /var/log/mysql.log indicate what the problem could be? It may be that another process is listening on the socket. If so we'll need to kill it.

Code:

netstat -nlp | grep 3306
#you should see something like the following line.
#tcp        0      0 127.0.0.1:3306          0.0.0.0:*               LISTEN      1456/mysqld
#Let's kill the process using it's pid (process ID).
kill -15 1456
#run the netstat command again, if the process does not go away after a while of running the netstat command then issue a force kill.
kill -9 1456
#try starting the mysql service again
service mysql start

southpointingchariot · 09-03-2012, 08:57 PM

Quote:

Originally Posted by sag47

Does /var/log/mysql.err or /var/log/mysql.log indicate what the problem could be? It may be that another process is listening on the socket. If so we'll need to kill it.

Code:

netstat -nlp | grep 3306
#you should see something like the following line.
#tcp        0      0 127.0.0.1:3306          0.0.0.0:*               LISTEN      1456/mysqld
#Let's kill the process using it's pid (process ID).
kill -15 1456
#run the netstat command again, if the process does not go away after a while of running the netstat command then issue a force kill.
kill -9 1456
#try starting the mysql service again
service mysql start

Opening mysql.err and mysql.log in vim reveals empty files.

Running "netstat -nlp | grep 3306" returns nothing.

And farther down the rabbit hole we go

.

sag47 · 09-03-2012, 08:59 PM

Code:

sudo apt-get purge mysql-server
sudo apt-get remove msyql-server
sudo apt-get install mysql-server

Let's try that way then. The "dmesg" command might indicate what could be going wrong as well.

southpointingchariot · 09-03-2012, 09:01 PM

Quote:

Originally Posted by sag47

Code:

sudo apt-get purge mysql-server
sudo apt-get remove msyql-server
sudo apt-get install mysql-server

Let's try that way then. The "dmesg" command might indicate what could be going wrong as well.

"sudo apt-get remove msyql-server" returns "E: Unable to locate package msyql-server". Isn't this logical concerning we just purged it?

Wim Sturkenboom · 09-03-2012, 09:01 PM

Quote:

When I run "mysql -u debian-sys-maint -p" I get "ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)"

Your daemon is not running; the netstat command also shows that.

sag47 · 09-03-2012, 09:02 PM

That's because it's spelled wrong, double check spelling, and try again. Should by mysql-server, and not msyql-server.

southpointingchariot · 09-03-2012, 09:05 PM

Quote:

Originally Posted by sag47

That's because it's spelled wrong, double check spelling, and try again. Should by mysql-server, and not msyql-server.

Ah, of course. It appears the installation was successful. Do I proceed with your earlier comment?

sag47 · 09-03-2012, 09:12 PM

Quote:

Originally Posted by southpointingchariot

Ah, of course. It appears the installation was successful. Do I proceed with your earlier comment?

Yes, hopefully with that everything should be okay. You might need to start the server,

Code:

sudo service mysql start

southpointingchariot · 09-03-2012, 09:15 PM

Quote:

Originally Posted by sag47

Yes, hopefully with that everything should be okay. You might need to start the server,

Code:

sudo service mysql start

Sigh, and we're back to "start: Job failed to start".

In case I'm missing something, the return from "sudo apt-get install mysql-server" was:

Quote:

Reading package lists... Done
Building dependency tree
Reading state information... Done
The following NEW packages will be installed:
mysql-server
0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded.
Need to get 0 B/11.7 kB of archives.
After this operation, 115 kB of additional disk space will be used.
Selecting previously unselected package mysql-server.
(Reading database ... 285829 files and directories currently installed.)
Unpacking mysql-server (from .../mysql-server_5.5.24-0ubuntu0.12.04.1_all.deb) ...
Setting up mysql-server (5.5.24-0ubuntu0.12.04.1) ...
root@jane:/var/log#

sag47 · 09-03-2012, 09:18 PM

The only thing I can think of left is maybe removing the /var/lib/mysql directory entirely.

Code:

#double check the path!  And double check it's not important!
sudo rm -rf /var/lib/mysql

Then try to start the mysql server again. Not unless you can give us more log information from dmesg or other mysql related log files.

southpointingchariot · 09-03-2012, 09:19 PM

Quote:

Originally Posted by sag47

The only thing I can think of left is maybe removing the /var/lib/mysql directory entirely.

Code:

#double check the path!  And double check it's not important!
sudo rm -rf /var/lib/mysql

Then try to start the mysql server again. Not unless you can give us more log information from dmesg or other mysql related log files.

To make 100% totally sure, does it matter what directory I'm in when I run this?

This part feels like brain-surgery by phone - and I'm the guy with the knife!

sag47 · 09-03-2012, 09:20 PM

It does not matter the directory you're in. Except do not be in the directory /var/lib/mysql. Be in any directory but that one.

sag47 · 09-03-2012, 09:22 PM

Also, forgot to mention but might want to try,

Code:

chown -R mysql\: /var/lib/mysql