Are You kidding guys ?from http://www.oracle.com/technetwork/database/database-appliance/oracle-database-appliance-faq-1903200.pdf
The Oracle Database Appliance X4-2 is a 4U rack-mountable system with two servers and one storage shelf. The two servers each contain two 12-core Intel Xeon Processors E5- 2697 v2 and 256 GB of memory for a total of 48 processor cores and 512 GB of memory per appliance The Oracle Database Appliance base configuration contains 18 TB of raw SAS storage, offering 9 TB double-mirrored or 6 TB triple-mirrored of resilient usable database storage. There are also four 200 GB solid state drives for high performance processing of database redo logs.and You want to switchover/failover to that from X3 in memory database ? :) Good luck . The only reason I can think of using ODA as DR for EXA is to have positive answer for Boss question 'do we have DR solution' ?
As DBA You can only pray disaster never happen :). Regards GG -- //www.freelists.org/webpage/oracle-l