If you need a new SSL certificate for a server you will need a 2048bit private key from 2011 onwards. This command creates both:
openssl req -new -nodes -newkey rsa:2048 -keyout example.key -out example.csr
Thats it send the CSR to you ISP and you should get you SSL cert back. You can also edit:
/etc/ssl/openssl.cnf
And change the default_bits line to 2048 then all new keys we be created with 2048bits.
Okay so you have forgotten your mysql root password and need to access you mysql server. This howto requires root access to the shell or via sudo:
First stop your mysql server via the init script:
/etc/init.d/mysql stop
Now lets start up the mysql daemon and skip the grant tables which store the passwords:
mysqld_safe --skip-grant-tables
You should be able to see mysql starting. Logon to mysql with the fowling command:
mysql --user=root mysql
Now change the password with:
update user set Password=PASSWORD('new-password') where user='root';
flush privileges;
exit;
Now kill your running mysqld, then restart it normally. You should be good to go. Try not to forget your password again.