General Information About The Ssa Raid Adapter, Ssa, And Raid - IBM B01 Service Manual

- - - ' -
SSA RAID Adapter, SSA, and RAID
General Information About the SSA RAID Adapter, SSA, and RAID
The IBM SSA RAID Adapter is a Peripheral Component Interconnect (PC I)
bus-master adapter that is the interface between the PCI architecture, and devices
that use the Serial Storage Architecture (SSA).
The adapter provides four SSA ports for the attachment of storage devices such as
hard disk drives. Each port operates at 20MB/s full-duplex, and uses point-to-point
copper cables that can be up to 25 meters long. SSA uses the SCSI-2 commands,
queuing model, status, and sense bytes; it is an industry-standard interface.
o
SSA
Loop
B
Port
2
f)
SSA
Loop
B
Port
1
D
SSA
Loop
A
Port
2
D
SSA Loop A Port 1
The adapter card has two pairs of SSA connectors, one pair (port 1 and port 2) for
each SSA 100p.3 Next to each pair of connectors is a light that functions as follows:
(
('
• The light is on continuously when power is turned on to the adapter and both
ports for that loop are operational; that is, the devices connected next to the
adapter in the loop have power turned on to them, are connected correctly to
the adapter, and are operational.
• The light flashes continuously if one of the ports is not operational. Such a
G
condition occurs if the cable to that port is not connected correctly, or if the
device that is connected next to the adapter in the loop is not operational.
• The light is off if both ports are not operational.
3
The
S/390
Integrated Server does not use Loop S, port 1 and port 2.
110
Service Guide