Dell PowerEdge 6850 - Manual (Page 7)

SAS Information Update
5
This document provides information about the optional Serial-Attached SCSI (SAS) hard drives, related
features, and procedures not covered in the system Installation and Troubleshooting Guide. The following
topics are covered:
• Features and indicators
• Installing SAS hard drives
• Replacing a SAS controller card
• SAS backplane boards
• SAS 2.5-inch peripheral interposer board
• Troubleshooting
Features and Indicators
The basic features and indicators are described in the system Installation and Troubleshooting Guide.
The key changes incorporated in systems with optional SAS hard drives include the following:
• Systems with SAS drives include a SAS controller expansion card, in place of the integrated SCSI
controller. SAS A and SAS B connectors on the backplane are connected to the SAS controller card.
• Systems with SAS drives include a SAS backplane for either the 3.5-inch or 2.5-inch SAS hard drives.
• RAID capability for systems with internal SAS drives is provided by the SAS controller expansion card.
• The RAID battery cable attaches to a connector on the SAS controller card, instead of to the battery
connector on the system board. See Figure 1-5.
• Systems with 2.5-inch SAS hard drives have the following additional changes incorporated:
– The 2.5-inch SAS backplane (see Figure 1-7) is connected to an additional board, the 2.5-inch SAS
peripheral interposer board (see Figure 1-10). The interposer board provides some of the
connectors included on the 3.5-inch backplane.
– The control-panel cable is routed under the bay for fans 1 and 3 and connected to the back of the
2.5-inch SAS peripheral interposer board. (For 3.5-inch drives the control-panel cable connects to
the front of the backplane on top of the hard drive bays.)
– The cooling shroud is modified to cover the space behind the hard drive bay, and cables and other
components are altered to accommodate the 2.5-inch drive bay and boards. Figure 1-1 illustrates
the inside of a 2.5-inch system.