Sidebar: Move to Itanium ... or Not

Computerworld - Many organizations using VMS have a mix of Alpha as well as aging VAX hardware to deal with. So, with HP porting VMS to Itanium 2 for its Integrity server line, companies must decide which way to go. Soldier on with VAX despite the lack of reseller support and a diminishing pool of spare parts, or port to Alpha? Retain Alpha systems for the seven remaining years HP promises to support them (HP says it will likely support Alpha until at least 2011), and then see where to go from there? Or move everything to Itanium and scrap a significant investment in VAX/Alpha-based VMS systems? Here are a few rules of thumb for the various scenarios.
1. Stay with VAX if you're constrained by hardware or software issues such as lost source code, special I/O hardware or large amounts of handcrafted assembler code.
2. "Consider emulation of VAX -- preferably on an Alpha/VMS platform, not Windows -- if the performance characteristics and availability requirements of the application allow you to," says Colin Butcher, a systems architect at XDelta.
3. Move from VAX to Itanium for "general purpose" applications without hardware constraints, but don't rush it. Spend time testing carefully, especially in high-availability and business-critical environments. But if you're moving to Itanium, then port from VAX to Alpha first in order to debug any 32-/64-bit problems and get the code through the compilers.
4. If your Alpha machines have room for growth in terms of performance (for adding CPUs or memory), then staying with them while you spend a couple of years planning and testing your port makes sense.
5. If you're about to buy new Alpha hardware, buy with room for growth so that you don't back yourself into a corner later on if your porting plans don't work out as intended. Such systems work well and are a known technology. "Alpha purchases are estimated to still be in the double-digit thousands of units sold each year," says consultant Terry Shannon.
6. Move from Alpha to Itanium-based systems if you gain advantages, such as performance (that's probably a few years away) and consolidation. Also be aware of support costs for Alpha, which will probably rise above those for Itanium boxes. However, don't rush to be the first to use the new systems unless you have some pretty good reasons to do so. "Most applications will migrate to Itanium with a minimum of effort, mainly recompilation," says Bob Gezelter, a software consultant in New York. "Programs which contain special Alpha- or VAX-specific code typically require modest changes."
7. If everything you need is supported on Itanium, then consider using it from Day 1, butbe aware that you'll be among the first to use it in a production environment. "It's all about assessing risk and striking an appropriate balance between risk and costs," says Butcher.

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