Likely Cause of NLM GFEs (Network Compatibility)

A customer of ours recently discovered a problem with an Advanced Revelation system running under Novell 4.10 and 4.11 with the Revelation NLM installed.  The system would randomly get a GFE in one of the files.  This was very strange because he NLM is designed to protect the system from file corruption.

 

Apparently this was being caused by a known problem with Novell versions 4.10 and 4.11.  This was originally discovered with BTRIEVE but is applicable to any database where multiple clients are simultaneously accessing a file.  By applying the patch from Novell, (see below)this should protect your AREV files from any potential file corruption. (please note that we have not had anyone report this problem with OpenInsight although we believe the same problem could potentially occur) Read the Tech Note below from Novell very carefully.  All Current Netware patches should be applied and this fix should be loaded in the startup.ncf (not autoexec.ncf) prior to volume mounting. 

 

PLEASE NOTE: ***These modifications are intended for NLM certified professionals only.  Revelation Software assumes no responsibility for damage resulting from improper application of these system changes.

 

The file can be located on Novell s Compuserve forum.  The file is called:

 

TURBOD.EXE

 

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NOVELL TECHNICAL INFORMATION DOCUMENT

 

TITLE:  TURBOD.EXE  for BTRIEVE database corruption

README FOR:  TURBOD.EXE

 

NOVELL PRODUCTS and VERSIONS:

NetWare 4.1

NetWare SFT III 4.1

NetWare 4.11

 

ABSTRACT:

 

This file contains the TURBODIS.NLM which prevents a corruption problem with

the turbo FAT.  The problem is typically seen on NetWare 4.10 and 4.11 file

servers with database applications which use large files.

 

 

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 DISCLAIMER

 THE ORIGIN OF THIS INFORMATION MAY BE INTERNAL OR EXTERNAL TO NOVELL.  NOVELL

MAKES EVERY EFFORT WITHIN ITS MEANS TO VERIFY THIS INFORMATION.  HOWEVER, THE

INFORMATION PROVIDED IN THIS DOCUMENT IS FOR YOUR INFORMATION ONLY.  NOVELL

MAKES NO EXPLICIT OR IMPLIED CLAIMS TO THE VALIDITY OF THIS INFORMATION.

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THIRD-PARTY HARDWARE CONFIGURATION

 

This problem is independent of any hardware configuration.

 

THIRD-PARTY SOFTWARE CONFIGURATION

 

NetWare 4.x and BTRIEVE applications

 

 

SYMPTOM:

 

NetWare 4.x customers who use BTRIEVE applications report STATUS 2 errors.  If

they dismount the volume with the corrupt file or use DOS COPY.EXE to copy the

file to another name or same name in another directory, the resultant file is

no longer corrupt.  In other words, they can use the BTRIEVE app on the

resultant file with no STATUS 2 errors.

 

TROUBLESHOOTING

 

One method of verifying that the STATUS 2 BTRIEVE errors are caused by a

corrupt turbo FAT is to use the DOS COPY.EXE to copy the corrupt file to a new

directory or different name in the same directory.   If the resultant file is

no longer corrupt, then the test proves that the turbo FAT was corrupt and the

TURBODIS.NLM file should be applied.  If the same corrupt file is copied using

NetWare's NCOPY.EXE, the resultant file will still be corrupt and the BTRIEVE

app will persist in STATUS 2 errors on the

 resultant file.

 

 The technical background for this test is as follows:

 

 1) NCOPY.EXE uses OS code which gets the file blocks using the turbo FAT.  If

the turbo FAT is corrupt, copying the file with NCOPY.EXE preserves the

corruption.

 

 2) COPY.EXE uses OS code which gets the file blocks from the FAT.  Copying the

file will bypass the corrupt turbo FAT and use the FAT which is not corrupt.

 

CAUSE

 

Some timing conditions due to multiple client access to a single file can cause

the turbo FAT for the file to get corrupt.

 

SOLUTION:

 

Apply the TURBODIS.NLM found in TURBOD.EXE on NSD.  TURBODIS.NLM will disable

the NetWare Turbo FAT creation thus preventing the Turbo Fat Corruption which

will produce the BTRIEVE status 2 errors.

 

Self-Extracting File Name: turbod.exe

 

Files Included     Size     Date      Time

 

..\

      TURBOD.TXT     (This file)

..\410\

    TURBODIS.NLM            1049          4-4-96      4:46:32 pm

..\411\

    TURBODIS.NLM            1044         2-11-97      4:00:00 pm

 

 

Installation Instructions:

 

Execute TURBOD.EXE.  Read the turbod.txt file.

 Apply the TURBODIS.NLM as you would any other dynamic patch.  Add a statement

to the STARTUP.NCF file which loads the TURBODIS.NLM from a local drive at the

time SERVER.EXE is executed.

 Example:  load c:\nwserver\patches\TURBODIS.NLM

 For NetWare 4.10 you will need to first apply the latest 410PTx.EXE patch kit.

For NetWare 4.11 you will need to apply the 411PTx.EXE patch kit.

 

 

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 Any trademarks referenced in this document are the property of their

respective owners.  Consult your product manuals for complete trademark

information.

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