How to combine multiple SNA subdomains into one subdomain by using Snacfg (222087)


The information in this article applies to:

  • Microsoft SNA Server 2.11
  • Microsoft SNA Server 3.0
  • Microsoft SNA Server 4.0
  • Microsoft Host Integration Server 2000
  • Microsoft Host Integration Server 2004
This article was previously published under Q222087

SUMMARY

In some cases, it may be beneficial to combine multiple SNA subdomains into one subdomain. Although the recommended method for doing this is to demote one primary SNA Server to a backup, have it join the desired subdomain, and then recreate its previous configuration (such as connections, users, LUs, and so on), it is possible to combine the Com.cfg files from the two primary servers so that the new backup server's configuration is retained. You can combine Com.cfg files by using Snacfg.exe, the SNA Server command line utility.

MORE INFORMATION

When combining the Com.cfg files from multiple SNA subdomains, there cannot be duplicate names of any of the following items:
  • SNA server names
  • Connection names
  • LU names
  • Shared folder share names
  • Print session names
  • Pool names
  • User names
  • Workstation names
  • Host security domain names
NOTE: If the Everyone group is configured under the Configured Users folder in SNA Manager, remove that group and re-add it in SNA Manager after the Com.cfg files have been combined.

In the following scenario, server A is the primary SNA server in subdomain A. server B is the primary SNA server in subdomain B, and it will be joining subdomain A as a backup server.
  1. On servers A and B, export each Com.cfg file to a text file using the following command:

    snacfg #[configpath] /print >filename.txt

  2. Save the text files, and name them so that you can tell which SNA server each corresponds to (for example, ServerA.txt and ServerB.txt).
  3. Open ServerB.txt in Notepad. On the Edit menu, click Select All, and then click Copy.
  4. In another Notepad window, open ServerA.txt. Move the cursor to the bottom of ServerA.txt, leave one blank line, and paste the text that was copied from ServerB.txt.
  5. On the File menu, click Save As, and name the combined text file (for example, Combined.txt).
  6. Copy the blank Com.cfg file from the SNA Server CD onto your hard drive. The file is located in the I386\System\Config directory on the CD.
  7. After you copy the blank Com.cfg, go into the properties of the file and clear the Read Only check box.
  8. Compile the text file containing the configurations of both SNA servers back into the blank Com.cfg file you copied from the SNA Server CD. To do so, run the following command from a command prompt:

    snacfg #[configpath] @combined.txt /v

    Note The configpath above is the path to the blank Com.cfg. The /v option stands for "verbose," and it is optional. If there are any errors in compiling the text file into the blank Com.cfg, /v will identify the line where the error is in the text file.
  9. The new Com.cfg now contains the configurations of both servers. The file may be viewed offline in SNA Manager. Verify that the configuration information looks correct. There are several items that you should check at this point:
    • If there are APPC print sessions configured, go into the properties of each of these print sessions, and re-enter the AS/400 User ID and Password on the Security tab.
    • If there are 3270 print sessions configured to use PDT files, go into the properties of each print session, select the Overrides tab, and click the PDT File button to browse and locate the PDT file. Select the PDT file, and then click OK.
    • If Host Security is configured, you may need to re-assign connections to the Host Security Domains. Also, you may need to re-add the user information in Host Account Manager.
    • If you removed the Everyone group from Configured Users, re-add it at this time. For each of the other users (and groups) run the following command from a command prompt:

      snacfg #[configpath] user /validate

      Note If the command above is not run for each user, the users may receive an error message saying "User is not configured" when they try to connect sessions to the SNA server, even though the users appear in SNA Manager and have LUs assigned to them.
  10. After you have verified that the new Com.cfg is ready to use:
    1. Stop the SnaBase service on server A and server B.
    2. Make backup copies of the existing Com.cfg files on each server (in case they need to be restored for any reason).
    3. Copy the new Com.cfg to the Sna\System\Config directory on server A.
  11. Delete the Snaexp.snav file from the Sna\System directory on server A and server B.

    This file will get recreated when SNA Manager is restarted. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

    175110 How to Change the Subdomain Name in SNA Server

  12. SNA server A (the primary) is ready to operate with the new Com.cfg at this point:
    1. On server B, from a command prompt, run svconfig.exe. This opens the Server Configuration dialog box.
    2. Demote server B to a backup server, enter the name of the primary server (server A), and enter the name of the subdomain that this server will be joining (subdomain A).
  13. Restart server B. It should now be functional as a backup server in subdomain A.
Modification Type:MajorLast Reviewed:5/3/2005
Keywords:kbhowto KB222087 kbAudDeveloper
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