Best way to back up mysql database

[Valentin Bud]

Hello list,

 I apologize if I somehow highjack the thread. I just want to tell the list
for further references
one way (my way) of doing mysql backup and to ask you if it's safe or not.

 I have 2 server: one of which is the master (named for the sake of brevity
with M) in mysql terms and the second being the slave (named with S).

 I use mysqldump on S and deliver the tarballs to a remote location. I first
stop the slave, do mysqldump
and start the slave.

Is this approach safe? Some might argue that it's not necessary or even
expensive somehow to have 2 boxes
*but* in my case I have 2 servers in production and one backups the other.

thanks for your input and have a great day,
v