HP Insight Management Agents - Manual (Page 52)

configuration change (e.g. mistakenly replacing a dual ported drive with a single ported
drive.)
◦ Erasing—Indicates that the logical drive is currently being erased.
◦ Unknown—You may need to upgrade your software.
When the status is Rebuilding one of the following values displays to indicate the progress of
the rebuild:
◦ Percent Rebuild Complete—Displays the percent complete of the rebuild. When the value
reaches 100, the rebuilding process is complete. The drive array continues to operate in
interim recovery mode while the drive is rebuilding.
◦ Rebuild Blocks Left—Displays the number of blocks of data that still need to be
redistributed. When the value reaches 0, the rebuilding process is complete. The array
continues to operate in interim recovery mode while the drive is rebuilding.
•
Rebuilding Drive—Identifies the physical drive that failed. The logical drive is rebuilding using
a spare drive in place of this failed drive.
When the status is Expanding one of the following values displays to indicate the progress of
the expansion.
◦ Percent Expand Complete—Displays the percent complete of the expansion. When a
logical volume is expanding, the drive must redistribute the logical volume data across
the physical drives. When the value reaches 100, the expansion process is complete.
◦ Expand Blocks Left—Displays the number of blocks of data that still need to be
redistributed. When the value reaches 0, the expansion process is complete. The array
continues to operate normally while the drive is expanding.
•
Fault Tolerance—Displays the fault tolerance mode of the logical drive. To change the fault
tolerance mode, run the Array Configuration Utility.
The following values are valid for the Logical Drive Fault Tolerance:
◦ None—(RAID 0) fault tolerance is not enabled. If a physical drive reports an error, the
data cannot be recovered by the Drive Array.
◦ Mirroring—(RAID 1/RAID 0+1) is the highest level of fault tolerance. It is the only method
offering fault tolerance protection if no more than two physical drives are selected. Drive
mirroring creates fault tolerance by storing duplicate data on two drives. There must be
an even number of drives. This is the most costly fault tolerance method because it requires
50 percent of the drive capacity to store the redundant data.
◦ Data Guarding—(RAID 4) assures data reliability while using only a small percent of the
logical drive storage capacity. A designated, single physical drive contains parity data.
If a drive fails, the controller uses the data on the parity drive and the data on the
remaining drives to reconstruct data from the failed drive. This allows the system to continue
operating with slightly reduced performance until you replace the drive.
◦ Distributed Data Guarding—(RAID 5) stores parity data across all the physical drives in
the array and allows more simultaneous read operations and higher performance than
data guarding (RAID 4). If a drive fails, the controller uses the parity data and the data
on the remaining drives to reconstruct data from the failed drive. The system then continues
operating with a slightly reduced performance until you replace the failed drive.
◦ Advanced Data Guarding—(RAID 6) 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
52 Agent information