Removal and replacement procedures 29
6.
Remove the BBWC enabler, also known as the battery pack.
To replace the component, reverse the removal procedure.
IMPORTANT:
The battery pack might have a low charge when installed. In this case, a POST error
message is displayed when the server is powered up, indicating that the battery pack is temporarily
disabled. No action is necessary on your part. The internal circuitry automatically recharges the batteries
and enables the battery pack. This process might take up to four hours. During this time, the cache module
functions properly, but without the performance advantage of the battery pack.
NOTE:
The data protection and the time limit also apply if a power outage occurs. When power is restored
to the system, an initialization process writes the preserved data to the hard drives.
Recovering data from the battery-backed write cache
If the server fails, you can recover any data temporarily trapped in the BBWC by using the following
procedure.
CAUTION:
Before starting this procedure, read the information about protecting against electrostatic
discharge ("
Preventing electrostatic discharge
" on page
17
).
1.
Perform one of the following:
•
Set up a recovery server station using an identical server model. Do not install any internal drives
or BBWC in this server. (This is the preferred option.)
•
Find a server that has enough empty drive bays to accommodate all the drives from the failed
server and that meets all the other requirements for drive and array migration.
2.
Power down the failed server ("
Power down the server
" on page
20
). If any data is trapped in the
cache module, an amber LED on the module blinks every 15 seconds.
CAUTION:
Do not detach the cable that connects the battery pack to the cache module. Detaching the
cable causes any unsaved data in the cache module to be lost.
3.
Transfer the hard drives from the failed server to the recovery server station.
4.
Remove the BBWC [cache module and battery pack] from the failed server.
5.
Perform one of the following:
•
Install the BBWC into an empty BBWC DIMM socket on the system board of the recovery server.
