Controller Settings

For links and interfaces common to all Configuration Wizards links, please see Wizards Overview in ACU help.

Note: These settings are also available during Standard Configuration under the Controller Settings link (once a controller has been selected). The options shown will vary depending on your controller's support for the various functions. However, Surface Scan Analysis Delay can only be set by using the Standard Configuration path as the option does not appear during the Configuration Wizards path.

During the following screens you will have the option to modify controller level settings. This will allow you to select the Rebuild Priority and Expand Priority, and the memory percentages for the Array Accelerator's read and write cache. Additionally, if your controller allows it, you can set a unique fibre array name for fibre channel controllers.

The first option is to select the desired Expand priority.

High
This radio button allows expansion to be performed at the expense of normal I/O. This option will allow the expansion to complete the fastest.

Medium
This radio button allows expansion to be performed with some impact on normal I/O.

Low
This radio button allows expansion to be performed only when normal I/O is not occurring. This option will cause the expansion to take the most time.

Note: As you increase the Expand Priority setting, requests from the operating system are serviced more slowly. Also, depending upon the type of Array Controller you are configuring, the Expand Priority section may not be available.

The second option is to select the desired Rebuild priority.

High
This radio button allows rebuilding to be performed at the expense of normal I/O. This option will allow the drive to complete rebuild the fastest.

Medium
This radio button allows the drive to be rebuilt with some impact on normal I/O.

Low
This radio button allows rebuilding to be performed only when normal I/O is not occurring. This option will cause the rebuild to take the most time.

Note: As you increase the rebuild priority setting, requests from the operating system are processed more slowly.

The third option is to select the desired memory percentages for the Array Accelerator's read and write cache.

The Accelerator Ratio determines the amount of memory allocated to the read and write caches. The options listed for Maximum Read and Write are dependent upon the type of controller you are configuring and the amount of memory installed on the Array Accelerator. Please note that if no logical drives have been set up to use the Array Accelerator the cache ratio settings will have no effect and will not be saved.

Although the choices vary upon the type of Array Controller you are configuring, available choices for the Accelerator Ratio are listed. For each option, the first value sets the percentage of the total amount of cache memory to the read-ahead cache; the second is dedicated to the percentage of write-back cache.

Only the battery-backed portion of the cache can be used for write-through cache. Accelerator ratio percentages are determined from the amount of write-through cache that is battery-backed. This varies with the type of controller and/or Array Accelerator that has been installed.

If the Array Accelerator has been permanently disabled, is not installed, or the controller has not yet been configured, this area is unavailable. In addition, if the controller has been enabled as an Online Recovery Server controller, the ratio is automatically set to the highest percentage of the read-ahead cache.

The following ratios may be available:

0 % Read, 100 % Write
10 % Read, 90 % Write
20 % Read, 80 % Write
25 % Read, 75 % Write
30 % Read, 70 % Write
40 % Read, 60 % Write
50 % Read, 50 % Write
60 % Read, 40 % Write
70 % Read, 30 % Write
80 % Read, 20 % Write
90 % Read, 10 % Write
100 % Read, 0 % Write

The fourth option if available is entering the RAID Array ID

RAID Array ID
Fibre Channel storage devices may be given a unique name. Use this field to enter a name for your storage array. If no name is entered, the storage array's serial number will be used (if available). This field may not be available if the storage array does not support or contain Fibre Channel controllers.

Surface Scan Analysis Delay
Note: This setting is only available under the Standard Configuration task path.

Surface Scan Analysis will scan drives whenever the controller is otherwise idle, and stops whenever I/O requests are received from the operating system. The amount of delay or idle time that the controller waits before resuming Surface Scan Analysis is configurable and measured in seconds. The default value is 15 seconds for scans that occur after the initial scan on newly-created, never scanned volumes.

Please note Surface Scan Analysis is performed only on configured logical drives. The value for the Surface Analysis Delay is only valid and can only be set when the controller contains configured logical drives.

A low delay may be necessary so that Surface Scan Analysis will make forward progress when the controller is part of a clustering configuration or in other situations where the operating system submits I/O requests to the controller at short regularly-spaced time intervals.