Product manual

Chapter 4: Management with WebPAM PROe
137
• Check the Enable Coercion box to enable disk drive capacity coercion.
For more information, see “Capacity Coercion” on page 349.
• Choose a coercion method from the Coercion Method dropdown menu.
The choices are:
GB Truncate – (Default) Reduces the useful capacity to the nearest
1,000,000,000 byte boundary.
10GB Truncate – Reduces the useful capacity to the nearest
10,000,000,000 byte boundary.
Group Rounding – Uses an algorithm to determine how much to
truncate. Results in the maximum amount of usable drive capacity.
Table Rounding – Applies a predefined table to determine how much to
truncate.
• Enter a time interval (1 to 12 seconds) in the Write Back Cache Flush
Interval field.
• Enter a time interval (15 to 255 seconds) in the Enclosure Polling
Interval field.
This is the time interval at which the controller polls all of the
components in the enclosure.
• Check the Adaptive Writeback Cache box to enable this feature.
• Enter a power level into the HDD Power Levels field. The choices are:
0 – Disables the feature. The read/write heads never park.
1 – Parks the read/write heads after the specified period of HDD Idle
Time.
2 – Parks the read/write heads and lowers rotation speed after the
specified period of HDD Standby Time.
3 – Parks the read/write heads, lowers rotation speed, and spins down
after the specified period of HDD Stopped Time.
• Enter an idle time period into the HDD Idle Time field.
1 to 1440 minutes or 0 to disable.
• Enter a standby time period into the HDD Standby Time field.
1 to 1440 minutes. or 0 to disable.
• Enter a stopped time period into the HDD Stopped Time field.
10 to 1440 minutes or 0 to disable.
• Check the Host Cache Flushing box to enable this feature.
When enabled, the controller immediately flushes the data in its cache
to the drives when the Host sends a Flush Cache command.
• Check the NCQ box to enable this feature.