StorCase Technology SCSI-to-SCSI Single RAID - Manual (Page 46)

36 Configuration
StorCase Technology, Inc. DXIFS-160/RAID User's Guide - Rev. B00
Battery
This command allows the user to run the controller without a battery. It is intended for use
only if the controller is run with a UPS so that loss of power is prevented. The default setting
is BATTERY ENABLED. If disabled, the controller will not give any warnings when it senses
that the battery is uninstalled, nor will it disable the writeback cache. If the setting is changed,
the controller will need to be rebooted.
Enable Trust Array
In order to use this command, the user must first enable the function from the Array Menu
(default setting is disabled). Once the Trust Array option is used for an array, the option is
automatically disabled.
Backoff Percent
This command allows the user to configure the backoff percentage of the array. It backs off
or reduces the capacity of the array by the given percentage. For example, a RAID 5 array
created with 10% backoff using three 10GB drives would yield an 18GB array -
[20GB-(20GB x 10%)] = 18GB. In this case, this allows the user to add a dedicated spare to
the array that is 9GB or larger (10GB-10%) in capacity.
The default setting is 1% backoff. This default allows the user to work easily with drives that
have the same nominal capacity, but different actual capacities. For example, two 18GB drives
from two different vendors may differ in capacity by 100MB. With a backoff of 0%, the user
would not be able to replace any array member's slightly larger 18GB drive with a smaller 18GB
drive. If identical drives from the same vendors are used, a backoff of 0% will work.
If the drives in an array are not equal in size, the array capacity in a RAID 5 array is based
on the smallest member's capacity. The backoff percentage is then backed off the capacity
from that amount.