mirrorDDP's are green.
The mirrorDDP series of products uses MAID ( Massive Array of Idle Disk) technology to save energy. Hard disks spin down when not in use for an adjustable amount of time and spin up when data request are apparent.
There are many different mirrorDDP versions. mirrorDDP's can be directly connected to the miniDDP's, Standalone DDP's and scalable (non) redundant DDP's. Data on these DDP's are synchronized on Archive DDP's. The synchronization process can be scheduled. In extreme situations, for example when the production DDP is out of order, the mirrorDDP's can temporarily be used as production DDP.