Users Guide

Configuring Controller Properties
You can configure the following properties for the controller:
• Patrol read mode (auto or manual)
• Start or stop patrol read if patrol read mode is manual
• Patrol read unconfigured areas
• Check consistency mode
• Copyback mode
• Load balance mode
• Check consistency rate
• Rebuild rate
• BGI rate
• Reconstruct rate
• Enhanced auto import foreign configuration
• Create or change security keys
NOTE: You can configure the Patrol Read Unconfigured Areas property using the iDRAC Web interface and not
RACADM.
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 currently undergoing one of the following:
• A rebuild
• A re-configuration 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.
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 at a later
time. 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.
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Managing Storage Devices