What is a disk group, a virtual disk, and a hot spare disk physical disk?

• A disk group is a set of disk physical disks that the  logically groups together to provide one or more virtual disks to an application .
• A virtual disk is a logical structure you create on a  for data storage. A virtual disk is defined over a set of disk physical disks called a disk group, and it has a defined  level and capacity. The disk physical disk boundaries of the disk group are hidden to the host computer.

  To better meet your application needs, you can configure additional virtual disk parameters, such as , , cache parameters, and .

• A hot spare disk physical disk contains no data and acts as a standby in case a disk physical disk fails in a , , , or  virtual disk. The hot spare disk physical disk adds another level of  to your storage array. If a disk physical disk fails in the storage array, the hot spare disk physical disk is automatically substituted for the failed disk physical disk without requiring a physical swap. If the hot spare disk physical disk is available when a disk physical disk fails, the RAID controller module will use redundancy data to reconstruct the data from the failed disk physical disk to the hot spare disk physical disk. When you have physically replaced the failed disk physical disk, a operation occurs. If you have designated the hot spare disk physical disk as a permanent member of a disk group, the copyback operation is not needed.

  A hot spare disk physical disk is not dedicated to a specific disk group but instead is global. You can use the hot spare disk physical disk for any failed disk physical disk in the storage array with the same capacity or smaller capacity.