NVRAM replacement behavior on a Sun Enterprise[TM] E3X00

Asset ID:	1-71-1017469.1
Update Date:	2010-06-08
Keywords:

Solution Type Technical Instruction Sure

Solution 1017469.1 : NVRAM replacement behavior on a Sun Enterprise[TM] E3X00 - Sun Enterprise[TM] E6X00

Applies to:

Sun Enterprise 3000-6000 PCI I/O Board
Sun Enterprise 3000 Server
Sun Enterprise 3500 Server
Sun Enterprise 4000 Server
Sun Enterprise 4500 Server
All Platforms

Goal

Description
Sun Enterprise 3x00-6x00 NVRAM/TOD (Time Of Day) chip information.

This document describes the functions of the NVRAM/TOD (Time Of Day) chip in a Sun Enterprise[TM] 3X00 - Sun Enterprise[TM] 6X00 system. It describes when it is needed to be replaced, what to expect during replacement, and how to copy idprom information from one TOD chip to another within the system.

Solution

Steps to Follow
Background information on the NVRAM or TOD Chip:

The component itself is a "M48T59 NVRAM" chip (pn 100-4007) and is located on the Clock Board and all I/O Boards in a Sun Enterprise 3X00-6X00 system. The component is actually a battery plus seeprom.

It is commonly called any one of several terms:

NVRAM chip
TOD (Time Of Day) chip
IDPROM
TOD NVRAM

The chip contains the following information:

hostid
ethernet address
OBP environment variables
time of day

How it functions:

Copies of this data reside on the Clock and all I/O Boards for redundancy. During the POST process, the NVRAM on the Clock Board is compared to the NVRAM(s) on the I/O Board(s). If the data on the Clock Board matches the data on at least one I/O Board, the data on the Clock Board is automatically synchronized to all I/O Boards.

In systems with only one I/O Board, it is important to follow the Clock Board replacement procedure correctly to retain the data located on the NVRAM chip. If the data is not retained, the hostid will change which will cause problems with software that uses hostid-based licensing.

If the Clock Board cannot find one I/O Board with matching NVRAM information when POST completes, the following message will be displayed:

  Clock TOD does not match TOD on any IO boards

This message refers to the TOD chip, not the time of day value. To rectify this, the NVRAM data needs to be copied.

Two OBP commands perform the copy function of NVRAM information:

  
  copy-clock-tod-to-io-boards

  I/O Board in hex> copy-io-board-tod-to-clock-tod

These commands only mention "tod"; this refers to the chip, not the time of day value. The copy-clock-tod-to-io-boards command copies the data from the Clock Board to all I/O Boards. The copy-io-board-tod-to-clock-tod command copies the data from the I/O Board specified (in hex) to the Clock Board.

The following scenarios explain how to copy the NVRAM/TOD data based on the part replacement performed:

1. When an I/O Board is replaced in a system with more than one I/O Board, the Clock Board will overwrite the TOD NVRAM on the new I/O Board so it is in sync with the rest of the system.

2. When an I/O board is replaced in a system with one I/O board,the Clock TOD does not match TOD on any IO boards error is always displayed.
Always run copy-clock-tod-to-io-boards to remedy this.
This propagates the TOD NVRAM information from the Clock Board to the I/O Board overwriting any information on the new I/O Board.
If the copy-io-board-tod-to-clock-tod command is used, the NVRAM data in the new I/O Board will overwrite the data in the Clock Board's NVRAM. All information previously stored in the Clock Board's NVRAM will be destroyed.

3. When replacing a clock board, it is advantageous to copy theNVRAM information from an existing I/O Board to the Clock Board using the copy-io-board-tod-to-clock-tod command.
If the copy-clock-tod-to-io-boards command is used instead, the data in the new Clock Board's NVRAM will overwrite all of the I/O Boards.

If the NVRAM data is copied incorrectly (ie. in the wrong direction), the following problems will occur:

* OBP variables will have to be reprogrammed
* Hostid and ethernet address will change.

This will create problems with software that has a license based upon the hostid

* Time of Day will change.

Upon initial bootup one may get a message, Last shutdown is later than time on time-of-day chip; check date.
This can cause severe problems for time based applications (ie. Oracle).

There is no way to verify the contents of the NVRAM chip on the Clock Board or the I/O Board. The banner command will show whatever POST has determined to be good data. POST will output a message (see below).

As mentioned before, the NVRAM chip has a built-in battery to retain its data. The only way to fix a dead battery is to replace the NVRAM chip (ie. replace the Clock or I/O Board). If the battery is dead, the following messages will appear during POST:

5,0>ERROR: TEST=NVRAM Devices,SUBTEST=M48T59 (TOD) Init ID=8.1
5,0>Component under test: Board 16 Firehose Bus
5,0>TODC battery is low bit set
Detected failed TOD on clock board. Using backup TOD on board in slot 1

NOTE: Patch 103346 contains the latest firmware (but hasn't been updated since March, 2006).

Product
Sun Enterprise 6000 Server
Sun Enterprise 5000 Server
Sun Enterprise 4000 Server
Sun Enterprise 3000 Server
Enterprise 3000-6000 PCI I/O Board
Sun Enterprise 6500 Server
Sun Enterprise 5500 Server
Sun Enterprise 4500 Server
Sun Enterprise 3500 Server

Internal Comments
In the US, view http://americasqual.central/qms/us/isodoc/sco/SCRP1016.html for the QMS NVRAM/SEEPROM Replacement Procedure.

NVRAM, TOD, NVRAM/TOD, hostid, ethernet, OBP, copy-clock-tod-to-io-boards, copy-io-board-tod-to-clock-tod
Previously Published As
73047

Attachments

This solution has no attachment