Tips on assigning hot spare physical disks

 must be of the same  as the physical disks they are protecting. For example, if you have a  expansion enclosure and a SATA expansion enclosure in the same , you must select hot spares to protect both types of physical disks. If you pick only Fibre Channel physical disks to use as hot spares, then none of the SATA physical disks will be protected.

Note: If there are no hot spares available that are the same physical capacity, then a physical disk with lower capacity may spare if the "used capacity" of the used physical disk is the same or smaller than the lower capacity hot spare.

Hot spares must have capacities equal to or larger than the physical disks they are protecting. For example, if you have an 18- GB physical disk with configured capacity of 8 GB, you could use a 9- GB or larger physical disk as a hot spare. However, if the configured capacity on the physical disk climbs to 12 GB, then a 9-GB hot spare would not be big enough if a physical disk failure were to occur. In this case, it would be ideal to have an 18 GB hot spare physical disk. Generally, you should not assign a physical disk as a hot spare unless its capacity is equal to or greater than the capacity of the largest physical disk on the storage array.