Compaq Storageworks Installing DIMMs in an HSG80 or HSZ80 Cache Module

This document provides instructions for replacing or upgrading Dual Inline Memory Modules (DIMMs) in the cache modules of Compaq HSG80 ACS Version 8.x and HSZ80 ACS Version 8.x Array Controllers.

The core procedure involves:

1. Preparation: Connecting a PC/terminal to the controller's maintenance port, disabling failover, and initiating the process using the FRUTIL utility.
2. Cache Module Removal: Selecting the appropriate option in FRUTIL to remove the cache module, waiting for device ports to quiesce (critical to prevent data loss), disengaging retaining levers, and carefully removing the module.
3. ECB Handling (Crucial): Disabling the External Cache Battery (ECB) by pressing a switch until its status light stops blinking before disconnecting/connecting the ECB cable to prevent battery damage.
4. DIMM Replacement: Once the cache module is removed, pressing the DIMM retaining levers and gently removing the old DIMM, then inserting the new DIMM straight into the socket, ensuring notches align and clips engage.
5. Cache Module Installation: Reinstalling the cache module into its slot, ensuring proper alignment to avoid backplane damage, and re-connecting the ECB cable.
6. Post-Installation: Using FRUTIL to confirm installation, enabling failover, setting subsystem date/time (for dual-redundant configurations), and restarting the other controller as needed.

Key Warnings and Considerations:

• ESD (Electrostatic Discharge): Always wear a grounded ESD wrist strap to prevent damage to DIMMs and cache modules.
• Data Loss: Ensure device ports are fully quiesced before removing cache modules to prevent data loss.
• ECB Damage: Strictly follow instructions for disabling and connecting the ECB; failure to do so can damage the battery.
• Time Limits: FRUTIL often imposes a 2-minute countdown for cache module removal and installation steps.
• Memory Configuration: For replacement, the new cache module must have the same memory configuration as the existing one. For HSG80 ACS Version 8.0, only 128 MB (4 x 32 MB) is a valid configuration.

The document details slightly varied procedures for HSZ80 ACS Version 8.1 and HSG80/HSZ80 ACS Version 8.2 Dual-Redundant Controllers, but the fundamental steps and warnings remain consistent.