DSM/Tape Catalog User's Guide

DSM/Tape Catalog User’s Guide — 520233-008

8 - 1

Storage Server Interface (SSI) to the

Tape Library Control Path

The Storage Server Interface process ($ZSSI) is the interface between the automated

cartridge system library software (ACSLS) that manages the storage and movement of

tape cartridges for tape libraries and the NonStop Kernel tape management process

$ZSVR.

$ZSSI translates and routes messages between the $ZSVR process on the NonStop

Kernel and the Client Server Interface (CSI) process on the ACSLS library server.

$ZSSI communicates with the CSI using RPC over TCP/IP and communicates with the

$ZSVR process through $RECEIVE. $ZSSI is used only by $ZSVR. Errors from the

tape library are returned to $ZSVR and logged in the EMS event log.

There is a one-to-one correspondence between $ZSVR and $ZSSI. $ZSSI is started

only by $ZSVR. $ZSSI is a persistent process because $ZSVR starts it. If $ZSSI stops,

$ZSVR automatically restarts it. $ZSSI is not a NonStop process; $ZSVR handles the

NonStop logic. Only $ZSVR sends messages to $ZSSI. There can be only one $ZSSI

subsystem on a node.

Functions and Features

The $ZSSI subsystem communicates through RPC over TCP/IP with the CSI software

component of the ACSLS library server software.

Request messages supported by $ZSSI are limited to those required by $ZSVR in its

support of the tape library. Support required by $ZSVR includes translating requests

and responses to these commands:

Topic Page

Functions and Features 8-1

Run-Time Configuration 8-2

Environment Variables 8-2

Startup Sequence 8-3

Running the Portmapper 8-4

Remote Procedure Call (RPC) Facility 8-6

Tape Library Error Diagnosis 8-8

Nonretryable Errors 8-9