@Danp yes I ran "yum update" to be sure but "nothing to upgrade" on the pool-master. I try with storage (iscsi) NIC configured and without Storage NIC configured but the pool join freeze. Seems that persist some "SESSION" (may be referred to the slave host previously configured?) or some incoerence in the pool database... from /var/log/xensource of the slave host when try to join the pool: "session_check D:520c5b4e5b36 failed with exception Server_error(SESSION_INVALID, "