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Ubuntu mysql cannot start after upgrade

Assalamu Allaikum

Well its quite a complicated problem, life was smooth and easy on ubuntu, when suddenly after upgrade to mysql-server-5.5, the mysql failed to start.

As a background info I must tell that I am using Windows 7 and ubuntu 12.04 on a single machine (dual boot) from different harddisks, and for web development I use single folder as IIS webroot (windows 7) and apache2 www (ubuntu). Same goes for mysql, I have single directory share for both windows and ubuntu.

However, after the upgrade, things got wrong in ubuntu and mysql failed to start. I check all the logs for mysql and there was no error.
Then I checked the logs for apparmor, because after ubuntu 10.04, apparmor needs to be clarified about the data dir of mysql, which I had done earlier, but to no avail. Nothing was mentioned there.
System log and kernal logs just showed that mysql cannot start.

To resolve the problem what I did Remember: I have different data dir then the default so I didn’t backup that, which otherwise may look like

sudo cp /var/lib/mysql ~/mysql-data

Then purge the installations

sudo aptitude purge mysql-common mysql-server mysql-client

Then simply remove the remaining folders

sudo rm /etc/mysql -R

now reinstall mysql from the scratch.

sudo aptitude install mysql-common mysql-server mysql-client

After the complete installation and configuration, I tried to again set the apparmor to change mysql datadir, but this somehow is not working now.
So the alternate is to run the following command

sudo ln -s /your-mysql-data-dir/* /var/lib/mysql

This will create a soft link for each file in your existing datadir to the ubuntu(/debian linux’s) mysql datadir. This way it will share the same data.

However, this approach has a few limitations.

  1. This will only work if you use windows mainly and create new databases there only. 
  2. For each new database You would have to run the last line again, I am looking for a way to attach this line as a script on mysql startup.



 Hope this resolves the problem.

Rehan Anis

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