Datacom VSAM Migration Tool - Implementation

This is article 3 of a 3-part series on using the Datacom VSAM Migration Tool. In this blog, we discuss the implementation process.

After Applying PTFs and performing the full planning functions, you are now ready to start implementing.

• NOTE: The Blog is specifically written to describe the processes and implement the VSAM Migration tool which is strictly used for Index and Data Areas. The system files (CXX, LXX, and FXX) use another process where you will be required to shutdown your Multi-User in order to perform the EXCP to VSAM LDS migration.  
  • We suggest you start by migrating the systems files prior to implementing the VSAM Migration tool (which migrates the Indexes and Data Areas only).
  • In order to perform the Systems Files migration, pick up member VSMCUS00 from your CABDSAMP target library. Copy it into your own library and make the adequate modifications and submit. Remember your Multi-User needs to be down in order to perform the migration of your system files (CXX, LXX, FXX).
  • If you’re planning on using the 24X7 utilities we would ask you to look into the sizing of your LXX. Specifically, for BA24 (Block Alter 24) and TM24 (Table Move 24) that requires every record modified to be logged. You’ll be able to get a feel as to the sizing aspects when performing these utilities in your sandbox.   OAM performs writes block at a time.
• Prior to the execution of any jobs, perform the following functions:
  • APF Authorize all the libraries that are included in the execution of DBUTLTY.
  • Execute a DBUTLTY with the following control card (This turns on VSAM support for Datacom):

CXXMAINT OPTION=ALTER,OPTION2=Y_VSAM 

• Pick up member VSMCUS01 from your CABDSAMP target library into your own private library. (Modify and execute) 
  • The execution of VSMCUS01 will create three libraries
    • HLQ.CUSVSAM (Place holder for the DBUTLTY MIGRATE tool process to consume.
    • It contains these three members which will be utilized with every step in the process. 

B15DDCXX -  Datacom System files
B15DDOUT -  DD statements to support job step
B15STLIB -  Datacom CUSLIB and Target libraries (All VSAM type processes require all STEPLIB libraries be APF authorized)

• • • HLQ.VSAM.MIGRJCL1 (This is where the MIGRATE tool will use to hold all of the JCL members to be created for the DBIDs being migrated.
    • The following members can be found in this library:
      •  JC      
      • LGNEW   
      • LGOLD   
      • MTNEW   
      • MTOLD   
      • MTPRE   
      • VSMCUS01
      • VSMMGRT
      • Modify all of the templates you’re planning on using. 
      • Please review everything described under the ‘INSTRUCTIONS:’ header. The JC member will also need to be modified for the job accounting information.
      • VSMMGRT job will request the template to be executed.

• • • • HLQ.SVSAM.MIGRJCL1.OUTPUT ( This library holds the generated jobs from the execution of the VSMMGRT job). Once these jobs are generated, they’re able to be executed against the DBIDs that were selected for migration.

Pros vs Cons:

The following scenario is specifically for environments that will not be able shutdown their bases to perform the migration but instead will need to use our 24X7 utilities which will make it possible for the migration to be executed while the bases are open, and the applications are available to the user community.

If you have Data Areas that are not 4k or a multiple of thereof and will need to use the 24X7 function OAM (Online Area Move).

Then you will need to convert your areas to 4k or a multiple of prior to executing the 24X7 function OAM (Online Area Move).

As mentioned in the first paragraph of this writing that Pros far outweighs the Cons. Specifically when most or all the Block sizes in your Data Areas are blocked at 4k or multiple of not to exceed 28k. This is a VSAM LDS requirement.

This is the third and final article in the Datacom VSAM Migration Tool Series. If you have not read the first two, please click here to read the Introduction article.