Allocate disk space for mirrored data

Before you can create a mirror chunk, you must allocate disk space for this purpose. You can allocate either raw disk space or cooked file space for mirror chunks. For an explanation of allocating disk space, see Allocate disk space.

Always allocate disk space for a mirror chunk on a different disk than the corresponding primary chunk with, ideally, a different controller. You can use this setup to access the mirror chunk if the disk on which the primary chunk is located goes down, or vice versa.