Digital Equipment StorageWorks UltraSCSI DS-BA370 Series, User Manual

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Operating the UltraSCSI Enclosure
2–2 Ultra SCSI RAID Enclosure
General
The following rules apply to the UltraSCSI bus:
1. The UltraSCSI RAID subsystems can transfer data at a higher rate
(40 MB/sec versus 20 MB/sec) than do the FAST 10 subsystems.
2. UltraSCSI subsystems require 68-pin VHDCI cables and connectors.
The physical difference in the contact spacing precludes using FAST 10
cables.
3. The following devices use a SCSI bus address and are SCSI bus
“nodes:”
•
Adapters
•
Controllers
•
Storage devices
4. Every node on a bus must have a unique SCSI ID.
5. The SCSI ID for controller “A” is always 7.
6. The SCSI ID for controller “B” is always 6.
7. There are slots for six 3.5-inch SBB nodes in a shelf. The address
switch on the PVA module determines node SCSI bus IDs. There is a
maximum of 12 valid DS–BA370 SCSI IDs—0 through 3 and
8 through 15.
8. A DS–BA370 UltraSCSI bus cannot support 5.25-inch devices.
9. With only UltraSCSI devices installed the maximum transfer rate of an
UltraSCSI bus is 40 MB/sec.
10. Installing a FAST 10 storage device limits the bus segment operations
as follows: