Upgrading from MySQL 5.1
Backup Current Data
Create a backup of your database
mysqldump --opt --all-databases | gzip > ~/mysqldump.sql.gz
Make a separate backup of the `mysql` database, which will come in handy if any recovery operations are required.
mysqldump --opt --databases mysql | gzip > ~/mysql.sql.gz
Also, make a copy of the MySQL configuration files
tar -C /etc -czf /etc/mysql.tar.gz mysql
Remove MySQL 5.1
Now that there are sufficient backups, MySQL 5.1 can be uninstalled.
aptitude purge mysql-server-5.1 mysql-client-5.1
The new InnoDB plugin provides Asynchronous I/O capabilities, but in order to take advantage of that, make sure libaio is installed
aptitude install libaio-dev libaio1
Install MySQL 5.5
Download the latest "Compressed TAR Archive" for your architecture at http://www.mysql.com/downloads/mysql/ (scroll to the bottom). At the time of this writing, 5.5.14 was the latest version.
Unpack this tarball to /usr/local
tar -C /usr/local -zxf mysql-5.5.*.tar.gz
Link it to /usr/local/mysql
ln -s /usr/local/mysql-5.5.* /usr/local/mysql
Fix the permissions
chown -R mysql: /usr/local/mysql
Link the bin tools to /usr/local/bin/
ln -s /usr/local/mysql/bin/* /usr/local/bin/
Copy the example MySQL configuration file to /etc
cp /usr/local/mysql/support-files/my-large.cnf /etc/mysql/my.cnf ln -s /etc/mysql/my.cnf /etc/my.cnf
Edit or add the following entries in /etc/mysql/my.cnf, plus any other required customizations. Also, look for any references to /usr/share/mysql, and update them to refer to /usr/local/mysql/share.
[client] socket = /var/run/mysqld/mysql.sock [mysqld] socket = /var/run/mysqld/mysql.sock user = mysql basedir = /usr/local/mysql datadir = /var/lib/mysql tmpdir = /tmp log_error = /var/log/mysql.err
Install the init script
cp /usr/local/mysql/support-files/mysql.server /etc/init.d/mysql chmod +x /etc/init.d/mysql update-rc.d mysql defaults
Start MySQL 5.5
Upgrade the internal table structures
Verify that all of your data looks good, and clean up the backups if you are happy with the results.