User's Manual

l Groups n disks as one large virtual disk with a capacity of (n-2) disks.
l Redundant information (parity) is alternately stored on all disks.
l The virtual disk remains functional with up to two disk failures. The data is reconstructed from the surviving disks.
l Better read performance, but slower write performance.
l Increased redundancy for protection of data.
l Two disks per span are required for parity. RAID 6 is more expensive in terms of disk space.
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Related Information:
See the following:
l "Organizing Data Storage for Availability and Performance"
l "Comparing RAID Level and Concatenation Performance"
l "Controller-supported RAID Levels"
l "Number of Physical Disks per Virtual Disk"
l "Maximum Number of Virtual Disks per Controller"
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RAID Level 50 (Striping over RAID 5 sets)
RAID 50 is striping over more than one span of physical disks. For example, a RAID 5 disk group that is implemented with three physical disks and then
continues on with a disk group of three more physical disks would be a RAID 50.
It is possible to implement RAID 50 even when the hardware does not directly support it. In this case, you can implement more than one RAID 5 virtual disks
and then convert the RAID 5 disks to dynamic disks. You can then create a dynamic volume that is spanned across all RAID 5 virtual disks.
Figure 3-6. RAID 50
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RAID 50 Characteristics:
l Groups n*s disks as one large virtual disk with a capacity of s*(n-1) disks, where s is the number of spans and n is the number of disks within each
span.
l Redundant information (parity) is alternately stored on all disks of each RAID 5 span.
l Better read performance, but slower write performance.
l Requires as much parity information as standard RAID 5.
l Data is striped across all spans. RAID 50 is more expensive in terms of disk space.
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Related Information:
NOTE: On the PERC 3/SC, 3/DC, 3/QC, 4/SC, 4/DC, 4e/DC, 4/Di, 4e/Si, 4e/Di, and CERC ATA100/4ch controllers, there are special considerations when
implementing RAID 50 on a disk group that has disks of different sizes. See "Considerations for RAID 10 and 50 on PERC 3/SC, 3/DC, 3/QC, 4/SC, 4/DC,
4e/DC, 4/Di, 4e/Si, 4e/Di, and CERC ATA100/4ch Controllers" for more information.