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z/OS Bimodal Migration Accommodation offering


   
 

Migration to z/OS

IBM is providing the z/OS Bimodal Accommodation offering in response to your requests for an alternative to running in 64-bit mode when first migrating to z/OS 1.2, 1.3, or 1.4 on a z/Architecture server ( z800, z890, z900, z990, or equivalent). Previously, z/OS had to run in 64-bit z/Architecture mode on a z/Architecture server. This offering gives you the security of knowing you can return to 31-bit mode if there are any 64-bit issues during your migration. The bimodal accommodation offering will not be provided for z/OS 1.5.

Download this offering from the Web!

This offering is only available for a 6-month period on each z/Architecture server. The 6 months begins when z/OS is licensed to the server. This offering will be available at no charge. You can download the Accommodation offering from the z/OS downloads Web page now.

Recommended migration paths

You can now migrate from OS/390 to z/OS on your 31-bit server (G5, G6, or Multiprise 3000) with the confidence that you can make a smooth transition to z/Architecture when you install z/Architecture servers in the future. When you install a zSeries server, your migration to z/Architecture is made simpler and more fail-safe with the Accommodation offering. The 6-month window begins when you license z/OS on a z/Architecture server.

64-bit mode on zSeries - Ready for business

IBM still recommends that you migrate directly to 64-bit z/Architecture mode when you install a z/800, z/900, or z990 if you are already running z/OS on a G5, G6, or Multiprise 3000 server. Significant testing has been completed since the introduction of 64-bit mode support with OS/390 2.10 in September 2000. z/OS 1.4 is the fourth z/Architecture release and many customers are running production systems in 64-bit mode. These environments include a long list of ISV products.

As with any migration, you should check all of your ISV products to validate their support on the new z/OS release. ISV products can require maintenance or a new release to run on the new z/OS release. It is expected that there should be very few situations where you'll need to fall back to 31-bit mode, but we're glad to provide this "safety net" to you to assist in your migration plans to move forward to z/OS.

z/OS in 31-bit mode - Functional limitation

The Bimodal Accommodation Migration offering does not extend support to those functions previously announced as requiring z/Architecture (64-bit). This includes, but is not limited to: Intelligent Resource Director, HiperSockets, 64-bit Real Storage, 64-bit Virtual Storage, and IPv6. In addition, Workload License Charges on z900 servers will not be available. z/OS.e is not supported by the Bimodal Migration Accommodation offering.



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z/OS Bimodal Accomodation offering FAQs

For more information, take a look at the z/OS Bimodal Accomodation offering FAQs [0.14MB]

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