Users Guide

• Check consistency rate
• Rebuild rate
• BGI rate
• Reconstruct rate
• Enhanced auto import foreign configuration
• Create or change security keys
You must have Login and Server Control privilege to configure the controller properties.
Patrol read mode considerations
Patrol read identifies disk errors to avoid disk failures, data loss, or corruption.
The Patrol Read does not run on a physical disk in the following circumstances:
• The physical disk is not included in a virtual disk or assigned as a hot spare.
• The physical disk is included in a virtual disk that is undergoing one of the following:
– A rebuild
– A reconfiguration or reconstruction
– A background initialization
– A check consistency
In addition, the Patrol Read operation suspends during heavy I/O activity and resumes when the I/O is complete.
NOTE: For more information on how often the Patrol Read operation runs when in auto mode, see the respective
controller documentation.
NOTE: Patrol read mode operations such as Start and Stop are not supported if there are no virtual disks available in the
controller. Though you can invoke the operations successfully using the iDRAC interfaces, the operations fail when the
associated job is started.
Load balance
The Load Balance property provides the ability to automatically use both controller ports or connectors connected to the same
enclosure to route I/O requests. This property is available only on SAS controllers.
Bgi rate
On PERC controllers, background initialization of a redundant virtual disk begins automatically within 0 to 5 minutes after the virtual
disk is created. The background initialization of a redundant virtual disk prepares the virtual disk to maintain redundant data and
improves write performance. For example, after the background initialization of a RAID 5 virtual disk completes, the parity
information has been initialized. After the background initialization of a RAID 1 virtual disk completes, the physical disks are mirrored.
The background initialization process helps the controller identify and correct problems that may occur with the redundant data
later. In this regard, the background initialization process is similar to a check consistency. The background initialization should be
allowed to run to completion. If cancelled, the background initialization automatically restarts within 0 to 5 minutes. Some processes
such as read and write operations are possible while the background initialization is running. Other processes, such as creating a
virtual disk, cannot be run concurrently with a background initialization. These processes cause the background initialization to
cancel.
The background initialization rate, configurable between 0% and 100%, represents the percentage of the system resources
dedicated to running the background initialization task. At 0%, the background initialization has the lowest priority for the controller,
takes the most time to complete, and is the setting with the least impact to system performance. A background initialization rate of
0% does not mean that the background initialization is stopped or paused. At 100%, the background initialization is the highest
priority for the controller. The background initialization time is minimized and is the setting with the most impact to system
performance.
Check consistency
The Check Consistency task verifies the accuracy of the redundant (parity) information. This task only applies to redundant virtual
disks. When necessary, the Check Consistency task rebuilds the redundant data. If the virtual disk is in a Failed Redundancy state,
running a check consistency may be able to return the virtual disk to a Ready state.
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