Recovery from a MySQL dump is too long !

[Bob Sauvage]

Hello *, 

My INNODB database has a size of 80GO. I've a replication setup on 3 slaves and I backup
my db from them. 
If a problem occurs on the database, a recovery from a dump takes around 6H ! That's too
long for us. 

2 ideas : 
1. Stop the slave and rsync the folder /var/lib/mysql to another server
2. Stop the slave, take a dump and when it's finish, pull the dump in another MySQL
instance daily. 

Do you have another ideas ? What's your advices ?

 Thanks in advance,