Many groups include disk resources for disks on shared buses. In some cases, these are simple physical disks, but in other cases they are complex disk subsystems containing multiple disks. Resources depend on the physical disk resource that represents the storage device. An unrecoverable failure of a disk resource results in certain failure of all resources that depend on that disk.
For these reasons, you might decide to use special methods to protect your disks and disk subsystems from failure. One common solution is the use of a hardware-based redundant array of independent disks (RAID). RAID support ensures the high availability of data contained on disk sets in your clusters. Some of these hardware-based solutions are considered fault tolerant, which means that data will not be lost if a member of the disk set fails.
Important
This section covers: