Selecting a RAID method
Not all controllers support all RAID levels. To determine the RAID capabilities of your controller, see the
model-specific information for your controller on the
Hewlett Packard Enterprise website
Most important
criterion
Also important
Suggested RAID level
Fault tolerance
Cost effectiveness
I/O performance
RAID 6
RAID 10 (ADM), RAID 1+0, RAID 50, RAID 60
Cost effectiveness
Fault tolerance
I/O performance
RAID 6
RAID 5 (RAID 0 if fault tolerance is not required)
I/O performance
Cost effectiveness
Fault tolerance
RAID 5 (RAID 0 if fault tolerance is not required)
RAID 10 (ADM), RAID 1+0, RAID 50, RAID 60
Alternative fault-tolerance methods
Your operating system may also support software-based RAID or controller duplexing.
•
Software-based RAID
resembles hardware-based RAID, except that the operating system works with
logical drives as if they were physical drives. To protect against data loss caused by physical drive
failure, each logical drive must be in a different array from the others.
•
Controller duplexing
uses two identical controllers with independent, identical sets of drives
containing identical data. In the unlikely event of a controller failure, the remaining controller and drives
will service all requests.
Neither of these alternative fault-tolerance methods supports online spares or automatic data recovery,
nor do they support auto-reliability monitoring or interim data recovery.
If you decide to use one of these alternative methods, configure your arrays with RAID 0 for maximum
storage capacity and refer to your operating system documentation for further implementation details.
Storage controller issues
General controller issues
Symptom
• The controller is not visible during the POST process.
• The controller shows errors during the POST process.
Cause
• The hardware is physically damaged.
• The controller is not supported on the server.
• The controller is not seated properly.
• The controller is faulty.
• The firmware is outdated.
Storage controller issues
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