Compaq StorageWorks UltraSCSI RAID Enclosure (DS-BA370 Series) User's Guide (EK-BA370-UG. C02, September 1998)

Operating the UltraSCSI Enclosure
2–2 UltraSCSI RAID Enclosure
• The following devices use a SCSI bus address (ID) and are SCSI
bus
nodes
:
— Adapters
— Controllers
— Storage devices
• Every node on a bus must have a unique
SCSI bus ID
.
• The SCSI bus ID for controller A is always 7.
• The SCSI bus ID for controller B is always 6.
• There are slots for six 3.5-inch disk drive SBB nodes in a shelf.
The address switch on the PVA module determines node SCSI
bus IDs. There are a maximum of 12 valid DS–BA370 SCSI bus
IDs—0 through 3 and 8 through 15.
• A DS–BA370 series UltraSCSI bus does not support 5.25-inch
devices.
• A DS–BA370 series enclosure does not support narrow devices.
• Only UltraSCSI devices have a maximum transfer rate of 40
MB/s.
• Installing a FAST 10 storage device reduces the bus average
transfer rate as follows:
— When the array controller communicates with a FAST 10
device, the transfer rate is at FAST 10 (the maximum rate this
device can handle).
— When the array controller communicates with a
FAST 20
device, the transfer rate is at FAST 20 (the maximum rate this
device can handle).
UltraSCSI RAID Controllers
The following general configuration rules apply to the UltraSCSI
RAID array controllers:
• The controller A SCSI bus ID is always 7.
• The controller B SCSI bus ID is always 6.