Decsystem 5100 Prestoserve/NVRAM Option Information

This document, "DECsystem 5100 PrestoServe/NVRAM Option Information" (First Edition, February 1991), serves as a comprehensive guide for installing, operating, and troubleshooting the PrestoServe/NVRAM option on the DECsystem 5100.

The PrestoServe/NVRAM option is a hardware and software solution that utilizes nonvolatile RAM (NVRAM) with battery backup as a disk write cache. This design significantly enhances input/output (I/O) performance and throughput, particularly for synchronous writes, while safeguarding against data loss due to power failures or system crashes. The option is licensed from Legato Systems, Inc.

Intended primarily for Digital Customer Services personnel and self-maintenance customers (who are responsible for installation and service), as well as general users, the manual is structured into four main chapters:

• Chapter 1: PrestoServe/NVRAM Option – Introduces the option, its components (NVRAM modules), and ordering information.
• Chapter 2: Installation – Provides step-by-step instructions for physically installing the NVRAM modules.
• Chapter 3: Operation – Details how to run power-up self-tests, interpret results, and use dedicated console commands like prcache for configuration and status checks.
• Chapter 4: Troubleshooting – Covers diagnostics (e.g., test 0x9), handling failed NVRAM modules, and procedures for recovering cache data.