You can mirror data only between the same types of storage.
When planning for mirroring of aggregates for systems that can use both array LUNs and disks, keep the following in mind:
The rules for setting up mirroring with disks are the same for FAS systems and V-Series systems.
You must follow the requirements for setting up SyncMirror with array LUNs, some of which are different from setting up SyncMirror with disks. After SyncMirror is set up properly, Data ONTAP can switch to using the mirrored storage without interruption in service if one or more LUNs on a storage array become unavailable.