What OS is your admin and client? Did you add the rac2 client using the mkhost command?
Try doing an "obtool updatehost -r -f rac2". If this does not work then you need to check that the time is in sync, no firewall is in the way and no other services are using the OSB ports. Check the /usr/tmp/observiced.log file on both the admin and client for possible reasons why the communication is failing.
As for the tape drive you need to explain exactly what your hardware setup is and include the output from "obtool lsdev -lvg" so we can start to look into what that problem is.
now i am trying to use my local disk as virtual tape as RND basis, is it possible?
i tried to do this following this doc ( http://docs.oracle.com/cd/E26569_01/doc.104/e21477/initial_config_domain.htm#CACEFABG)
but i have to implement this on solaris spark machine running SAP and with sun tape drive.
OSB does not include a virtual tape device and does not yet support backing up directly to a disk device, so you have to attach and configure a supported tape device. You can also use virtual tape devices, assuming you have installed one from the list of supported VTL providers.