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HP Insight Management Agents User Manual

Page 82

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Fault Tolerance displays the fault tolerance mode of the logical drive. To change the fault
tolerance mode, run the System Configuration Utility.

The following values are valid for the Logical Drive Fault Tolerance:

None - Fault tolerance is not enabled (referred to as RAID 0). If a physical drive reports
an error, the data cannot be recovered by the drive array controller.

Mirroring - For each physical drive, there is a second physical drive containing identical
data (also known as RAID 1). If a drive fails, the data can be retrieved from the mirrored
drive.

Data Guarding - One of the physical drives is used as a data guard drive and contains
the exclusive OR of the data on the remaining drives (also known as RAID 4). If a failure
is detected, the drive array controller rebuilds the data using the data guard information
plus information from the other drives.

Distributed Data Guarding - Distributed data guarding (sometimes referred to as RAID 5)
is similar to data guarding, but instead of storing the parity information on one drive, the
information is distributed across all of the drives. If a failure is detected, the Drive Array
Controller rebuilds the data using the data guard information from all the drives.

Advanced Data Guarding - (RAID ADG) is the fault tolerance method that provides the
highest level of data protection. It stripes data and parity across all the physical drives
in the configuration to ensure the uninterrupted availability of uncorrupted data. This
fault-tolerance method is similar to RAID 5 in that parity data is distributed across all
drives in the array, except in RAID ADG the capacity of multiple drives is used to store
parity data. Assuming the capacity of 2 drives is used for parity data, this allows continued
operation despite simultaneous failure of any 2 drives in the array, whereas RAID 4 and
RAID 5 can only sustain failure of a single drive.

Unknown - You may need to upgrade your software.

Capacity displays the size of the logical drive.

Accelerator indicates whether the logical drive has an Array Accelerator board configured
and enabled. The following values are valid:

Enabled - The Array Accelerator board is configured and enabled for this logical drive.
Run the System Configuration Utility to change this value.

Disabled - The Array Accelerator board is configured but not enabled for this logical
drive. Run the System Configuration Utility to change this value.

Unavailable - There is no Array Accelerator board configured for this logical drive.

Unknown - The Storage Agents do not recognize the Array Accelerator board. You may
need to upgrade your software.

Stripe Size displays the size of a logical drive stripe in kilobytes.

OS Assigned Name displays the operating system name associated with this logical drive.

Preferred Path displays the preferred controller path to this logical drive in a redundant
active/active configuration. The preferred path is only relevant when the Preferred Path Mode
is configured as Manual.

Current Path displays the current controller path to this logical drive in a redundant active/active
configuration.

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Agent information