Battery-Backed Write Cache Enabler - HP ProLiant DL580 Setup And Installation Manual

Battery-Backed Write Cache Enabler

A BBWCE is included in some models with the Smart Array 5i Plus Controller. Also
called the battery module, this component enables write cache, provides transportable
data protection, increases overall controller performance, and maintains any cache
data for up to 72 hours.
NOTE: The data protection (and the time limit) also applies if a power outage occurs. When
power is restored to the system, an initialization process writes the preserved data to the hard
drives.
The NiMH batteries in the battery module are continuously recharged through a
trickle charging process whenever the system power is on. Under normal operating
conditions, the battery module lasts for 3 years before replacement is necessary.
IMPORTANT: The battery module may have a low charge when it is first installed. In this
case, a POST message 1794 is displayed when the server is powered up, indicating that the
array accelerator is temporarily disabled. No action is required on your part, since the internal
circuitry automatically recharges the batteries. The recharge process can take up to 24 hours.
The array controller will function properly during this time, although without the performance
advantage of the array accelerator. When the batteries are charged to 79 percent of their
capacity, the array accelerator is automatically enabled.
The battery module can be removed from the server without using any tools. For
detailed instructions, refer to "Installing the Battery-Backed Write Cache Enabler" in
Chapter 5, "Installing Hardware Options."
CAUTION: When using the battery module, observe the following limitations:
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The battery module has two LEDs, one green and one amber. When the battery
module is connected to the controller and the server is powered up, the green LED
indicates the status of the battery charge. When the battery is connected to the
controller and the server is powered down, the amber LED indicates the status of the
data retention. Refer to "Battery-Backed Write Cache Enabler" in Appendix E,
"System LEDs and Switches," for more information.
HP ProLiant DL580 Generation 2 Server Setup and Installation Guide
Do not transfer the battery module between different server models.
Do not add or remove the battery module while array capacity expansion, RAID
level migration, or stripe size migration is in progress.
Smart Array 5i Plus Controller
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