Open SCSI Integrator's Manual for NonStop S-Series Servers

Overview

Open SCSI Integrator’s Manual for NonStop Servers—422988-002

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The External Open SCSI Bus Interface

The Open SCSI I/O process (IOP) software supports passthrough capability for an

application. This means that an application can send commands to a device using SCSI

command descriptor blocks (CDBs). Using this software, an application can

communicate with a device using the FILE_OPEN_, FILE_CLOSE_, and

WRITEREAD[X] Guardian procedure calls. The Open SCSI passthrough software

provides the ability to open, close, read, and write files and to handle system messages.

The Open SCSI implementation is not device-specific. User applications can control any

type of SCSI-2 device attached to a SCSI controller. Open SCSI devices are configured

using the Subsystem Control Facility (SCF).

The Open SCSI I/O interface software is supported by G03.00 and subsequent G-series

software releases.

Figure 1-2. Dual-Path Open SCSI Bus Configuration

Note. The Open SCSI bus does not support SCSI-1 devices.

SCSI port

Processor 0

External device

(no terminator required)

SCSI bus

SCSI port

Processor 1

102CDT .CDD