Specifications

For details on models and operating system versions and releases that the ESS
supports for these host systems, see the following Web site:
www.storage.ibm.com/hardsoft/products/ess/supserver.htm
General information about attaching to an open-systems host with
SCSI adapters
The following section provides information about attaching an ESS to your SCSI
open-systems host.
For configuration limitations for the host systems, see the IBM Enterprise Storage
Server Introduction and Planning Guide. Also see “SCSI host system limitations” on
page 11.
Cable interconnections
Figure 3 on page 8 shows how a single SCSI bus connects between an ESS and a
set of SCSI devices. Each SCSI adapter card in an ESS has a built-in terminator.
You can configure each SCSI bus that is attached to the ESS independently.
The attached SCSI devices might be initiators (hosts) or target devices. The
ESS supports a maximum of four SCSI target devices on any wide SCSI bus. IBM
recommends that you use one SCSI initiator per SCSI bus on an ESS. The number
of SCSI devices that the ESS controller uses on the bus is determined by the
number of targets specified in the logical configuration for that bus. The SCSI
adapter card in the ESS operates in target-only mode.
Note: If you have multiple hosts attached to the same SCSI bus, IBM strongly
recommends that you use the same type of host. If you have different hosts
on the same SCSI bus, you must use the same type of host adapter. For a
list of adapters see the following Web site:
www.storage.ibm.com/hardsoft/products/ess/supserver.htm
Chapter 1. Introduction 7