Seems like questions for Exadata specialist. If you have got the valid question bank certified by CertGuard, the answer should be there in it. Also, check for the same in the Exadata documentation.
Agree 'Database Machine' means this is an Exadata question.....
... thread moved from Database General Questions to Exadata.
(your duplicate re-post has been removed)
You'll definitely want to reference the Exadata documentation, and this link to an Oracle Exadata migration best practices document can be helpful to: http://www.oracle.com/technetwork/database/features/availability/xmigration-11-133466.pdf. Having said that, if I were answering this question, I would say because you are going to need to convert the byte order from Big Endian on HPUX to Little Endian on Exadata/Linux and because on Exadata best practice is to have a 4MB AU size as opposed to the 1MB on the source you will want to go with a logical migration instead of a physical migration... so the two logical migration answers using streams or a logical standby would be candidates.