- IBM switch Users and Maintenance Guide

valid for the drive loop. The amber Conflict LED (located on the right-side of
the switch) will be lit if another unit in the drive loop has the same ID setting
as the server ID.
Attention: When connecting the DS4100 to DS4000 EXP100 storage expansion
units, DO NOT use the tens digit (x10) setting. Use only the ones digit (x1) setting
to set unique server IDs or enclosure IDs.
Give each drive expansion enclosure in a redundant drive loop a unique ones digit
(x1) ID. This setting will enforce hard AL_PAs (unchangeable between fibre channel
Loop Initializations [LIPs]) for the drives and facilitate drive loop problem
troubleshooting in the event of an error. If the ones digits are not unique, two or
more devices will have the same hard AL_PA. In such a case, the controller will use
soft AL_PAs for the devices that have identical hard AL_PAs.
The problem with soft addressing is that addresses may change between LIPs. This
possibility increases the difficulty of troubleshooting drive loop problems, since one
cannot easily ascertain whether the same device with a different address or
different device may be causing a problem.
Storage server speed settings
The default switch setting is 2 Gbps. This is the only speed setting allowed for the
DS4100.
Attention: Do not remove the metal plate that covers the storage server speed
setting. Do not adjust the storage server speed setting.
Configuring the storage subsystem
You must configure the storage subsystem configuration after you install the storage
server in a rack cabinet. Use the information in the following sections to configure
your storage subsystem configuration.
Storage subsystem management methods
Before you configure the storage subsystem, determine which method of storage
subsystem management you want to use. You can manage the storage subsystems
in either of two ways: host-agent (in-band) management or direct (out-of-band)
management.
Important: If the operating system of the host server that the storage subsystem
logical drive(s) is mapped to is not Microsoft
®
Windows NT
®
, you have
to make a direct (out-of-band) management connection to the storage
subsystem to set the correct host type first. Then, the server will be
able to recognize the storage subsystem correctly for host-agent
(in-band) management.
Host-agent (in-band) management method
This method requires host-agent software that you install on the host server. The
host-agent software allows the DS4000 Storage Manager client program to manage
the DS4000 storage subsystem using the same fibre channel connections between
the host server and the storage subsystem. You must install at least one
management station and a software agent host. The management station can be
the host or a workstation on the Ethernet network. A management station will have
the client software installed. Figure 23 on page 35 shows the host-agent (in-band)
management method.
34 IBM TotalStorage DS4100 Storage Server: Installation, User’s, and Maintenance Guide