IBM 7133 Series, Service Manual

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|
Addressing SSA Disk Drives
| This section describes how SSA devices and adapters are known to the using system
| programs.
Location Code Format
Location codes identify the locations of adapters and devices in the using system and its
attached subsystems and devices. These codes are displayed when the diagnostic
programs isolate a problem. For information about the location codes that are used by the
using system, see the Operator Guide for the using system.
This section shows the location codes for the 7133.
A B - C D - E F - G H
│ │ │ │ │ │ │ │
│ │ │ │ │ │ │ └──── Always
│ │ │ │ │ │ │
│ │ │ │ │ │ └────── Always
│ │ │ │ │ │
│ │ │ │ │ └────────── Always
│ │ │ │ │
│ │ │ │ └──────────── P = Physical disk drive module
│ │ │ │ L = Logical disk drive
│ │ │ │
│ │ │ └──────────────── Adapter position (number of the slot, 1 through 8, containing
│ │ │ the SSA adapter
│ │ │
│ │ └────────────────── System I/O bus identifier
│ │
│ └────────────────────── Always
│
└──────────────────────── Always
The location code shows only the position of the SSA adapter in the using system and the
type of device that is attached. The location of the device (disk drive module) must be
found by use of a service aid. The service aid uses the IEEE-standard 16-digit unique ID
of the device.
Pdisks, Hdisks, and Disk Drive Module Identification
The physical disk drives (pdisks) in an SSA subsystem can be configured as logical units
(LUNs). A LUN is also known as an hdisk, and can consist of one or more physical disk
drives. An hdisk in an SSA subsystem might, therefore, consist of one pdisk or several
pdisks.
| The configuration software also allocates an identification (hdisk and pdisk number) to
| each disk drive module during the configuration of the SSA loop. The disk drive modules
| do not have fixed physical addresses.
The numeric identifiers of pdisks, hdisks, and the disk drive module slots of a 7133 are not
related to each other. For example, pdisk1 is not necessarily installed in slot 1 of the
7133.
| The system software recognizes the disk drive module by a machine-readable number that
| is written on the electronics card of the disk drive module. This number is shown also on
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7133 Service Guide