Q293879: "Unable to Write File" Error After Changing Com.cfg

Article: Q293879
Product(s): Microsoft SNA Server
Version(s): 4.0,4.0 SP1,4.0 SP2,4.0 SP3,4.0 SP4
Operating System(s): 
Keyword(s): kbDSupport sna4 kbsna400sp1 kbsna400sp2 kbsna400sp3 kbhis2000 kbsna400sp4
Last Modified: 08-MAY-2002

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The information in this article applies to:

- Microsoft SNA Server, versions 4.0, 4.0 SP1, 4.0 SP2, 4.0 SP3, 4.0 SP4 
- Microsoft Host Integration Server 2000 
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SYMPTOMS
========

Attempting to save an SNA Server or Host Integration Server 2000 configuration
file (Com.cfg) after making a configuration change results in an "Unable to
write file" error.

The configuration changes that were made are not saved in the configuration.

CAUSE
=====

If the addition of a new APPC mode causes the amount of memory needed to store
APPC mode records to exceed 64 KB in the SNA Server/Host Integration Server 2000
configuration file, a calculation is done to resize the amount of memory needed.
This calculation is being done incorrectly, which prevents the addition of more
APPC mode definitions.

RESOLUTION
==========

SNA Server 4.0
--------------

A supported fix is now available from Microsoft, but it is only intended to
correct the problem described in this article and should be applied only to
systems experiencing this specific problem. This fix may receive additional
testing at a later time, to further ensure product quality. Therefore, if you
are not severely affected by this problem, Microsoft recommends that you wait
for the next Microsoft SNA Server version 4.0 service pack that contains this
fix.

To resolve this problem immediately, contact Microsoft Product Support Services
to obtain the fix. For a complete list of Microsoft Product Support Services
phone numbers and information about support costs, please go to the following
address on the World Wide Web:

  http://support.microsoft.com/default.aspx?scid=fh;EN-US;CNTACTMS

NOTE: In special cases, charges that are normally incurred for support calls may
be canceled, if a Microsoft Support Professional determines that a specific
update will resolve your problem. Normal support costs will apply to additional
support questions and issues that do not qualify for the specific update in
question.

The English version of this fix should have the following file attributes or
later:

+-----------------------------------+
| File name  | Date       | Time    | 
+-----------------------------------+
| Snacfg.dll | 03/21/2001 | 05:34PM | 
+-----------------------------------+

NOTE: Because of file dependencies, the most recent fix that contains the above
files may also contain additional files.



Host Integration Server 2000
----------------------------

No fix is yet available for this problem in Host Integration Server 2000.

STATUS
======

SNA Server 4.0
--------------

Microsoft has confirmed this to be a problem in Microsoft SNA Server versions
4.0, 4.0 SP1, 4.0 SP2, 4.0 SP3, 4.0 SP4.

Host Integration Server 2000
----------------------------

Microsoft has confirmed this to be a problem in Microsoft Host Integration Server
2000.


MORE INFORMATION
================

The problem described in this article may occur when you are making any number
of configuration changes if the SNA Server or Host Integration Server 2000
configuration file contains a large number of objects. However, the number of
objects at which this problem may occur cannot be provided here because it
depends on various other configuration variables.

The following are examples of two scenarios that result in the "Unable to write
file" error:

- Adding new APPC Mode definitions to the SNA Server/Host Integration Server
  2000 configuration.

- Assigning existing LUA (logical unit application) LUs to existing LUA pools.

  NOTES: In this case, no new objects were added to the SNA Server/Integration
  Server 2000 configuration.

  The error occurs because the new association created by assigning the LUA LUs
  to the LU pools required additional memory to store the objects.

For additional information on another problem that can cause an "Unable to write
file" error when you save an SNA configuration file, click the article number
below to view the article in the Microsoft Knowledge Base:

  Q314973 "Unable to Write File" Error Message Is Displayed After You Add Local
  APPC LU

Additional query words:

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Keywords          : kbDSupport sna4 kbsna400sp1 kbsna400sp2 kbsna400sp3 kbhis2000 kbsna400sp4 
Technology        : kbAudDeveloper kbSNAServSearch kbHostIntegServ2000 kbSNAServ400 kbSNAServ400SP1 kbSNAServ400SP2 kbSNAServ400SP3 kbSNAServ400SP4
Version           : :4.0,4.0 SP1,4.0 SP2,4.0 SP3,4.0 SP4
Issue type        : kbbug
Solution Type     : kbfix

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