ORACLE Shifting from from one version to another
Since you upgrade your OS, at some point you need to relink your Oracle software. In that case, easiest is to make a new software installation on the new server. Unmount the luns where the database is located from the old server and mount that on the new server where the database files should be mounted on the same locations as on the old server.

I hope that the ORACLE_HOME is not on the same lun[s] as where the database is located. If ORACLE_HOME does exist on the same LUN[s], make sure to create the new ORACLE_HOME on a different PATH and make sure that config files like /etc/oratab and listener.ora reflect this change.

This should give the quickest migration.
If there is to be done more than just re-mount the LUN[s], make sure to have a capable DBA involved. That will save you a lot of downtime and problems.