For the purposes of DR, consider two types of memory.
kernel memory cage
non-kernel memory cage
These two types differ only in usage. The actual hardware is the same for both types. Kernel memory cage is the memory that is used by the Solaris Operating System. Sun Cluster software does not support remove-board operations on a board that contains the kernel memory cage and rejects any such operation. When a DR remove-board operation pertains to memory other than the kernel memory cage, Sun Cluster software does not reject the operation. When a DR add-board operation that pertains to memory succeeds, memory on the added board is automatically incorporated in system operation.