PowerEdge System Components

Integrated PERCs

The PowerEdge 2500, 2550, 4400, and 4600 support optional integrated PERCs on the system board. PowerEdge servers may also contain PCI card PERCs occupying an expansion slot on the system board.

RAID controllers may be connected either to an external drive enclosure or to hard drives contained within the server chassis itself. PERCs that support multiple channels may be connected to internal drives as well as external drives, provided all SCSI rules are observed.

Another name for an Integrated RAID controller is a ROMB (an acronym standing for RAID On MotherBoard). The PERC 3/Di is the only integrated RAID controller currently available on PowerEdge servers.

Systems that support integrated RAID controllers may have the optional ROMB enabled at the time of system purchase or at a later date. If an integrated PERC is not enabled, it will function as a SCSI controller and not a RAID controller.

A RAID enabler kit may be ordered from Dell and installed to allow RAID functionality. If the onboard RAID is ordered when the PowerEdge server is purchased, the onboard RAID components will be installed by Dell prior to delivery. The RAID kit consists of:

• The RAID key, a small circuit board that is plugged into a special slot on the system board, enabling RAID functionality.

• Cache memory in the form of a DIMM that is inserted into a special RAID memory slot on the system board.

• A cache battery that preserves the controller's cache memory contents in the event of a loss of power to the server during read/write operations.

  

  
  PowerEdge System Board, detailing the Cache Memory, RAID Key, and Cache Battery

The RAID battery should be disconnected before reseating or removing the RAID memory. The RAID battery should also be installed AFTER the RAID memory when a RAID kit is being installed.