This method is most useful when data loss is unacceptable but cost is also an important factor. The
probability that data loss will occur when an array is configured with RAID 6 (ADG) is less than it would be if it
were configured with RAID 5.
This method has the following benefits:
• It is useful when data protection and usable capacity are more important than write performance.
• It allows any two drives to fail without loss of data.
RAID 60
: RAID 60 is a nested RAID method in which the constituent hard drives are organized into several
identical RAID 6 logical drive sets (parity groups). The smallest possible RAID 60 configuration has eight
drives organized into two parity groups of four drives each.
For any given number of hard drives, data loss is least likely to occur when the drives are arranged into the
configuration that has the largest possible number of parity groups. For example, five parity groups of four
drives are more secure than four parity groups of five drives. However, less data can be stored on the array
with the larger number of parity groups.
The number of physical drives must be exactly divisible by the number of parity groups. Therefore, the
number of parity groups that you can specify is restricted by the number of physical drives. The maximum
number of parity groups possible for a particular number of physical drives is the total number of drives
divided by the minimum number of drives necessary for that RAID level (three for RAID 50, four for RAID 60).
All data is lost if a third drive in a parity group fails before one of the other failed drives in the parity group has
finished rebuilding. A greater percentage of array capacity is used to store redundant or parity data than with
non-nested RAID methods.
This method has the following benefits:
• Higher performance than for RAID 6, especially during writes.
• Better fault tolerance than either RAID 0 or RAID 6.
• Up to 2n physical drives can fail (where n is the number of parity groups) without loss of data, as long as
no more than two failed drives are in the same parity group.
Storage Pool
: A storage pool is the aggregation of physical drives into a RAID group. When a HPE
StoreEasy 1X60 system physical disks have been configured into one or more hardware-based RAID array
configurations, the Windows operating system will see these RAID array logical drives as one or more storage
pools. The tools that will be used for creating and managing the storage pools are:
System Architecture
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