HP DL785 - Manual (Page 47)

IMPORTANT: The battery pack might have a low charge when installed. In this case, a POST
error message displays when the server is powered up, indicating that the battery pack is
temporarily disabled. No action is necessary. The internal circuitry automatically recharges the
batteries and enables the battery pack. This process can 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” (page 23) ).
1. Perform one of the following tasks:
• 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. 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 module ( “Removing the cache module” (page 45) ) and battery pack
( “Removing the BBWC battery pack” (page 45) ) from the failed server.
5. Perform one of the following tasks:
• Install the BBWC into an empty BBWC DIMM socket on the system board of the recovery
server.
• Install the BBWC into an empty BBWC DIMM socket on any Smart Array Controller
in the recovery server.
6. Power up the recovery server. A 1759 POST message displays, stating that valid data was
flushed from the cache. This data is now stored on the drives in the recovery server. You
can now transfer the drives (and controller, if one was used) to another server.
Power supply backplane
To remove the power supply backplane:
1.
Power down the server ( “Power down the server” (page 25) ).
2. Remove the server from the rack ( “Removing the server from the rack” (page 26) ).
3. Remove the access panel ( “Removing the access panel” (page 27) ).
4. Remove all power supplies ( “Power supply” (page 38) ).
5. Disconnect all cables from the power supply backplane.
6. Slide the retaining bracket to the rear of the server.
7. Lift the backplane, slide the board over the anchoring pins, and lift the board straight out
of the server.
Power supply backplane 47