Yes, backup/restore is your only option in this scenario.
The actual config is a RAID-1 with one spare disk (3 NL SAS disks are installed) with w2012 and Oracle on it. I would like to speed up this server with changing the array to RAID-10 (4x SAS 10k disks). Could it be as simple as making an iso backup from the actual array, removing the RAID-1 disks, installing the new disks, configuring the RAID-10 after pressing CRTL-R at boot, restoring the ISO image and probably reactivating the op. system?
Disk array changing process tips asking for Perc H700 in PET310