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

Single-Ended I/O Module
UltraSCSI RAID Enclosure 5–9
Cabling an UltraSCSI Subsystem
This section provides procedures for adding a second and third
enclosure (expansions) to a subsystem. The first expansion enclosure
connects to the master enclosure. A second expansion enclosure
connects to either the master enclosure or the first expansion
enclosure. Before beginning any cabling installation, complete the
preliminary procedures in Table 5–3.
Caution
Not all array controllers support an UltraSCSI RAID
subsystem with more than one enclosure. Refer to the array
controller documentation to ensure the controller supports
expanded configurations.
The Compaq UltraSCSI controller does not support
connecting or disconnecting a SCSI bus cable when both
data and power are present on the connector—a hot swap.
Only connect or disconnect SCSI bus cables using the cold
swap method.
Caution
To ensure proper UltraSCSI bus operation, Compaq
recommends a maximum cable length of 2 m (6.6 ft).
Table 5–3 Preliminary Cabling Procedures
1. Determine how many enclosures will be connected to the master
enclosure (0, 1, or 2).
2. Determine if a second master enclosure will connect to the master
enclosure or the first expansion enclosure.
3. Determine the optimum route for each UltraSCSI bus cable.
4. Use Table 5–4 to select the UltraSCSI cable for each segment—based
upon the distances between the enclosures.