HP P3410A - NetRAID 1M RAID Controller Installation And Configuration Manual page 26

Chapter 2
RAID 10 Disadvantages
Costs are high, because 50% of all disk space is allocated for redundancy.
Capacity expansion is an offline operation only.
RAID 10 Summary
RAID 10 provides the best performance for most applications where
redundancy and large logical drive size are required, and cost is not a factor.
RAID 50: Spanning with Distributed Parity
A RAID 50 configuration combines multiple RAID 5 arrays into a single storage
space. A distributed parity algorithm within each RAID 5 array provides data
redundancy. The data is striped across all the RAID 5 arrays that constitute the
RAID 50 logical drive. For example, if your RAID 50 configuration spans two
RAID 5 arrays, data blocks are written as follows:
Disk
1
Stripe
Block
1
1
Stripe
Block
7
2
Stripe Block
13
3
RAID 50 Advantages
There is no data loss or system interruption due to disk failure, because if
one disk fails, data can be rebuilt.
Capacity equivalent to only one disk in each array of the RAID 50 logical
drive is required to provide redundancy.
RAID 50 lets you create large logical drives:
With the HP NetRAID-1M adapter, the total number of disks in the
RAID 50 logical drive is limited by the number of disks that can be
attached to its single SCSI channel. For example, if a Rack Storage/12
enclosure is used, the maximum number of disks in a RAID 50 logical
drive is 12.
18
Spanned Array (RAID 50)
Array 1 (RAID 5)
Disk Disk Disk
2 3 4
Block Block Parity
2 3
1-3
Block Parity Block
8 9
7-9
Block Block
Parity
14 15
13-15
RAID Overview
Array 2 (RAID 5)
Disk Disk Disk
5 6 7
Block Block Block Parity
4 5 6
Block Block Parity Block
10 11
10-12
Block Block Block
Parity
16 17
16-18
Disk
8
4-6
12
18