Users Guide

• Copyback mode
• Load balance mode
• Check consistency rate
• Rebuild rate
• BGI rate
• Reconstruct rate
• Enhanced auto import foreign conguration
• Create or change security keys
You must have Login and Server Control privilege to congure the controller properties.
Patrol read mode considerations
Patrol read identies 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 reconguration 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, congurable 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
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Managing storage devices