IBM totalstorage 200, Service Manual

Page: 82 / 180

Replacing the ServeRAID controller
This section provides illustrations of the SCSI channel connectors and cable
connectors for the ServeRAID-4H and ServeRAID-4L controllers.
ServeRAID-4H controller connector locations
The ServeRAID-4H controller has four independent SCSI channel connectors:
Channel 1, Channel 2, Channel 3, and Channel 4. Each of these SCSI channels
supports up to 15 physical devices.
Note: The battery-backup cache protects the data being stored in the ServeRAID
cache memory during a power outage or failure when using the write-back
mode.
In the ServeRAID-4H controller, an internal SCSI device is attached to channel 1.
This means you cannot attach an external SCSI device to channel 1.
Note: The ServeRAID-4H controller uses the module (P/N 38L3386) containing a
lithium battery.
Statement 2
CAUTION:
When replacing the lithium battery, use only IBM Part Number 33F8354 or an
equivalent type battery recommended by the manufacturer. If your system has
a module containing a lithium battery, replace it only with the same module
type made by the same manufacturer. The battery contains lithium and can
explode if not properly used, handled, or disposed of.
Internal Channel 2
Internal Channel 1
Battery-backup cache
External Channel 1
External Channel 2
External Channel 3
External Channel 4
Figure 25. ServeRAID-4H controller
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Models 200 and 225 Service Guide