OpenVMS to Windows Migrations

For organizations using applications under OpenVMS on VAX or Alpha, and planning to move to Intel or AMD servers family based processors, there are basically two options: A native migration, or a VAX virtualisation product running under Windows and creating a "Virtual VAX". In cases where the application's source code is not available, the VAX Emulator must be used. In cases where the source code is available, a native migration is certainly the more preferable option, allowing for future expandability and ease of maintenance.

The following overview can be used as a decision support matrix:

 NATIVE MIGRATION EMULATION
General
The original application is completely ported to the target platform and becomes a native application on Windows. Partial redesign, optimization, language conversion, middleware replacement, etc. can be applied as needed.
CHARON-VAX for Windows is a family of virtualization software products that create virtual VAX systems on Windows. The application remains as-is, and is executed under OpenVMS/VAX running on the "Virtual VAX" created by CHARON-VAX.

Requirements and Limitations

 NATIVE MIGRATION VIRTUALIZATION
Application's source code
Required.
Not needed.
Application's Programming Language
Can be automatically converted into a modern programming language. Please see SRI's programming language conversion services
Irrelevant
Layered products and Middleware used by the application
A partial re-design can be applied to modernize the application.
Irrelevant
Special hardware used by the application
Partial re-design can be applied to eliminate the necessity of special hardware.
The special HW must either be supported on the target platform, or some programming will be needed using CHARON-VAX's Application Programming Interface (CHAPI).
Application's mode of code
Irrelevant.
Irrelevant.
Other requirements and limitations
None
Will depend on individual case. Please contact SRI.

Migration Process / Duration / Cost

 NATIVE MIGRATION VIRTUALIZATION
Migration process organization
Software Resources International will be able to extend a fixed price, fixed delivery date quotation for application migration. Please see SRI's Application Migration Services.
Please contact Software Resources International or the nearest Value Added Reseller of SRI.
Migration process duration
Project duration and schedule will depend on the size and complexity of the application. Will be defined during the project assessment phase.
The installation and configuration of CHARON-VAX can be performed on-site during 1 to 2 calendar weeks by one of SRI's or SRI's certified VAR's specialists.
Efforts & Cost
Project cost will depend on the size and complexity of the application. Will be defined during the project assessment phase.
Various product variations are available depending on the application's needs. Please contact Software Resources International or the nearest Value Added Reseller of SRI.

Conclusions

 NATIVE MIGRATION VIRTUALIZATION
Pro
  • Produces native application on the target platform
  • Minimum limitations.
  • Almost every application can be migrated.
  • Partial redesign during migration allows for replacing the programming language, middleware, user interface and design.
  • Extends the life cycle of the application.
  • Further development and maintenance on modern target platform.
  • Gives a performance boost
  • Retains the original application development environment "as is"
  • Doesn't need the source code
  • Inexpensive.
  • Does not need significant migration efforts
  • Usually increases performance
Contra
  • May take longer to implement
  • Source code needed
  • Maintenance of the application requires retaining OpenVMS/VAX knowledge
  • Future development of application must be performed under OpenVMS/VAX running on CHARON-VAX.
  • Any special HW used must either be supported on the target platform, or the Application Programming Interface CHAPI must be used.
Suitable for
  • Large and complex applications, developed in more than one programming language, and using layered products
  • Systems, where only a hardware upgrade is required
  • Applications created using proprietary programming tools which are too expensive for a native migration