Sun Microsystems StorEdge 3000 Series, Руководство по установке

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6-16 Sun StorEdge 3000 Family FRU Installation Guide • May 2004
Caution – SCSI IDs are based on the cabling of the array when the array is powered
up. If you are removing host connections from a dual-host dual-bus multi-initiator
configuration, use terminators to preserve the existing SCSI ID assignments (as well
as the termination on the bottom SCSI ports).
To keep other host connections operational while one host connection is temporarily
removed, perform the following steps.
1. Stop all host I/O activity on the host bus where the removal of a cable will occur.
2. Disconnect the array from the host SCSI cable of the server that requires the
maintenance work from the array.
3. Insert the external terminator into the empty SCSI port on the array.
The external terminator preserves the original SCSI IDs.
4. Resume host I/O activity on the remaining host(s).
6.6.2 Older JBOD Dual-Bus Configurations
If you have earlier I/O modules and do not have JBOD I/O modules part number
370-5396-02/50 or higher, use the information in this section.
Note –
The older I/O modules only supported single-initiator dual-bus
configurations.
In a dual-bus configuration, the SCSI IDs change according to the termination on the
SCSI ports. If your original configuration has both SCSI ports connected on a bus
connected to host(s), the SCSI IDs are 0 to 5. If only the bottom port is connected to
a host, the SCSI IDs are 8 to 15. To preserve all original SCSI IDs and correct
termination on a dual bus JBOD in a cluster environment, insert an external
terminator in all cases where a top SCSI port is empty but was not empty in the
original configuration.
Note –
As a general rule, external terminators are necessary in JBOD configurations
(for JBOD configuration information, refer to the Sun StorEdge 3310 SCSI Installation,
Operation, and Service Manual ). The two bottom SCSI ports on the JBOD are typically
terminated with an HBA host connection or a SCSI jumper cable. The upper I/O
SCSI connectors are autoterminated. Single-bus JBOD cabling does not require an
external terminator at any time; only the dual-bus JBOD cabling in the cluster
environment has the one condition where external terminators are required.