User manual

Controller
Setting Description
Controller
Setting Description
Controller ID
ID of the controller for which settings are to be configured. The ID
itself is not configurable.
Alias
Allows you to create a name for the DataGuard Appliance.
Enable SMART
Log
Check the box to enable or uncheck to disable SMART Log.
SMART Polling
Interval
Enter a value of 1 to 1440 minutes in this field to set SMART
polling frequency.
HDD Power
Levels
Choose the following options:
• Level 0: Disabled
• Level 1: Park R/W heads
• Level 2: Slow down (must be supported on HDD)
• Level 3: Spin down
Spin Down
Type
Determines which hard drives spin down when idle: all hard
drives or spare
hard drives only.
Power Saving
Idle Time
How long disks can be idle before putting them into standby
mode.
Power Saving
Standby Time
How long disks can be in standby mode before they are put
in stopped mode.
Power Saving
Stopped Time
How long disks can be in stopped mode before shutting down
the system.
Enable
Coercion
for fault-tolerant
logical drives
(RAID 1, 5, 6).
If possible, use hard drives of the same size, speed, make and
model in your disk arrays. Hard drives of different sizes will work
but the system must reduce or coerce the capacity of the larger
drives to match the smaller ones.
Capacity Coercion also allows you to use a replacement drive
that is up to 1GB smaller than the working drive it backs up. For
example, a working drive can be 80.5GB and the replacement
drive can be 80.3, since all are rounded down to 80GB. Without
Capacity Coercion, the controller will not permit the use of a
replacement drive that is slightly smaller than the remaining
working drives.
Coercion
Method
Choose a method from the drop-down menu:
• 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.
Write Back
Cache Flush
Interval
An interval for periodic controller flushes of the write cache
to logical drive storage. This safety measure prevents the
accumulation of data in cache that could be lost in the event of
power loss.Enter a value of 1 to 12 seconds in this field; be aware
that shorter intervals might affect applications in which read/write
performance is crucial.
Phydrv Driver
Temperature
Threshold
Enter a temperature threshold value from 50 to 60 degrees
Celsius. This is a temperature tolerance level that applies to
the temperature of the physical drives.
Enclosure
Polling
Interval
The interval at which the array controller polls the environmental
services processor in the enclosure. Default value is 15 ms; valid
values are 15–255 ms.
Adaptive
Writeback
Cache
Adaptive Writeback Cache:
• UPS power good: write back
• UPS power fail: write through
• No UPS: write through
Host Cache
Flushing
Used to optimize data reliability, but can cause dropped frames
when using high bandwidth, low latency tolerant or real-time
applications. Disable this feature if the DataGuard Appliance is
used as file storage for video editors or video capture software.
To reduce the risk of data loss with host cache flushing disabled,
connect the DataGuard Appliance to an uninterruptible power
supply (UPS).
Forced Read
Ahead
Can improve performance for multiple stream backup and
sequential I/O. Use with logical drive read ahead enabled.
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