new percona cluster with excisting data

H everyone

I am building up a staging percona cluster with three servers from a test database taken from xtrabackup (includes grastate files, etc) . The relevant database is about 30G and what i did was to copy the data files on all servers to the /var/lib/mysql/ directory and changed ownership to mysql

I bootstrap the first server and then when i start the second server it starts SST process.

How can i avoid the SST process?
Also, since the data are exactly the same, why does the joiner starts SST?

Thanks

Well i must been doing something wrong in the whole procedure because when i tried again it work without any issues.

This article may be useful here:
http://www.percona.com/blog/2012/08/02/avoiding-sst-when-adding-new-percona-xtradb-cluster-node/