This doesn't work at scale. The IO performance with LVM is terrible. I lost a lot of money trying to implement this. Percona wrote Xtrabackup as a replacement for LVM.

Documentation:

http://www.mysqlperformanceblog.com/2009/02/05/disaster-lvm-...

http://www.mysqlperformanceblog.com/2009/02/24/xtrabackup-op...