Now you can restart mysqld with the --skip-grant-tables option so that you can set a new password. There are two alternative ways to do so: either the mysqladmin tool, by way of
$ mysqladmin -u root password 'mynewpassword' $ mysqladmin -h hostname flush-privileges
You should now be able to connect using the new password. Test this!
One final step remains: stop mysqld and restart it normally.
See also: MySQL Manual: A.4.2 How to reset the Root Password
mysql in some configurations can log all database activity to a binary log file (usually in /var/lib/mysql). If you have a busy site this can grow quite large. The recommended management solution in the mysql manual is to remove binary log files that you no longer want. They suggest removing files that are older than 3 days. To remove all binary log files you can use the following command
RESET MASTER ;
If the mysql_error() PHP function returns
Got error 28 from table handler
this means your disk runneth over. Probably /tmp. Go clear it out.
One page links to MySQLNotes:
lib/main.php:944: Notice: PageInfo: Cannot find action page