Raid Levels - HP Surestore Disk Array 12h - And FC60 Advanced User's Manual

using a 5-disk RAID 5 LUN, a stripe segment size of 32 blocks (16
entire I/O would fit on a single stripe (16
The total stripe size is the number of disks in a LUN multiplied by the stripe segment size.
For example, if the stripe segment size is 32 blocks and the LUN comprises five disks, the
stripe size is 32 X 5, or 160 blocks (81,920 bytes).

RAID Levels

RAID technology uses a number of different techniques for storing data and maintaining
data redundancy. These industry-standard RAID levels define the method used for
distributing data on the disks in a LUN. LUNs that use different RAID levels can be created
on the same disk array.
The Disk Array FC60 supports the following RAID levels:
•
RAID 0
•
RAID 1
•
RAID 0/1
•
RAID 3 (Windows NT and Windows 2000 only)
•
RAID 5
RAID 0
RAID 0 does not provide data redundancy. It should only be used in
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situations where high performance is more important than data protection.
The failure of any disk within a RAID 0 LUN will cause the loss of all data on
the LUN.. RAID 0 should only be used for non-critical data that could be lost
in the event of a hardware failure.
RAID 0 uses disk striping to achieve high performance. Data is striped across all disk in the
LUN. The ability to access all disks in the LUN simultaneously provides a high I/O rate. A
RAID 0 group configuration for a logical disk unit offers fast access, but without the high
availability offered by the other RAID levels.
Unlike other RAID levels, RAID 0 does not provide data redundancy, error recovery, or
other high availability features. Consequently it should not be used in environments where
high-availability is critical. All data on a RAID 0 LUN is lost if a single disk within the LUN
Disk Array High Availability Features
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