Specifications

Cable interconnection hints and tips
The following is a list of hints and tips for cable interconnections:
v Host time-outs might occur due to bus contention when there are too many
initiators that try to drive excessive loads over a single bus. The four-initiator limit
allows each host to run a significant amount of work without incurring time-outs
on I/O operations.
v Your host system might have configuration requirements on the number and type
of SCSI devices on the SCSI bus other than what you can do on the ESS.
v You can attach a host system to multiple ports through a separate SCSI bus
cable and a separate SCSI adapter for each port.
v You cannot use the configuration in Figure 3 for the AS/400 and iSeries. See
“Recommended configurations for the AS/400” on page 46 for information about
how to configure an AS/400 and iSeries.
v The SCSI adapter card in an ESS does not provide terminator power
(TERMPWR) for the SCSI bus to which it is connected.
v Each host system you attach to a single SCSI bus must be a compatible host
system.
v The SCSI adapter card in an ESS provides its own power for termination.
v The host adapter in the ESS has a built-in terminator. Therefore, you do not
require external terminators.
v The SCSI adapter card in an ESS must always be at one end of the SCSI bus to
which it is connected.
v Each device on a SCSI bus must have a unique ID. Before you attach any
device to a SCSI bus, ensure that it has a unique ID for the bus to which you
want to connect.
Other SCSI bus on host adapter
Other SCSI bus on host adapter
Other SCSI bus on host adapter
SCSI bus
SCSI bus
HA
HA
HA
SCSI
host
SCSI
host
SCSI
host
SCSI
host
SCSI
host
2105 Model
E10, E20,
F10 and F20
Single controller on a bus
Two controllers on a bus
T
T
T
T
T
T
T=SCSI Terminator
HA=host adapter
2105 Model
E10, E20,
F10 and F20
2105 Model
E10, E20,
F10 and F20
T
VS08043N
Figure 3. ESS host interconnections
8 ESS Host Systems Attachment Guide