Dell MD3200 RAID Controller Module-Additional Features, Battery Backup Unit, Component Function

Item	Component	Function
18	SAS IN 3 port	Lights green when all four links are connected.
	link/fault LED	Lights amber when one to three links are disconnected.
		Off when all links in the port are disconnected or cable is
		disconnected.
19	Management	Lights green when ethernet connection is operating at 1000
	port speed LED	Mbps.
		Lights amber when ethernet connection is operating at 100
		Mbps.
		Off when ethernet connection is operating at 10 Mbps or is
		not active.
20	Management	Lights green when ethernet connection is active.
	port activity LED	Off when ethernet connection is not active.
21	Management	Provides a 100/1000 Mbps Ethernet connection for out-of-
	port Ethernet	band management of the enclosure.
	connector

RAID Controller Module—Additional Features

Battery Backup Unit

Each RAID controller contains a two-cell lithium ion nanopolymer battery backup unit (BBU). It provides power to the RAID controller module in the event of a power outage, see "RAID Controller Module Backup Battery Unit" on page 202.

NOTE: For virtual disks, the RAID controller firmware changes the data cache setting based on the state of the battery. If the battery is missing or does not have sufficient charge, the controller flushes the cache and sets the write cache attribute to Write Through for all virtual disks. When the battery is replaced, Write Back is re-enabled.

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Planning: RAID Controller Modules